Health

Thyroid Disorder Clues You Can’t Ignore

47. Slow Growth in Children Thyroid hormones are essential for normal growth and development in children. They regulate bone growth, brain maturation, and overall physical development.… Diana Yasinskaya - August 22, 2025

Thyroid disorders affect approximately 20 million Americans, with many cases remaining undiagnosed. The thyroid, a butterfly-shaped gland at the base of the neck, regulates vital bodily functions through hormone production. Unfortunately, symptoms often develop gradually, making detection difficult until the condition becomes advanced. Late recognition of these disorders can lead to serious health complications. Early awareness of subtle warning signs is crucial for timely intervention and management of thyroid health. Understanding these clues can help prevent long-term consequences and improve overall well-being.

1. Persistent Fatigue

1. Persistent Fatigue
A sleepy woman rests her head on her hand at a desk, her tired eyes struggling to stay open. | Generated by Google Gemini

Thyroid hormones, namely thyroxine (T4) and triiodothyronine (T3), play a pivotal role in regulating the body’s metabolism and energy production. When these hormone levels are imbalanced—either too low (hypothyroidism) or too high (hyperthyroidism)—the body’s cells do not receive the energy they need to function optimally. This often results in persistent fatigue, even after sufficient sleep or rest. Unlike the temporary tiredness most people experience after a busy day or a late night, thyroid-related fatigue is ongoing, unexplained, and can significantly impact daily activities.

For example, someone experiencing hypothyroidism might find themselves needing extra hours of sleep yet still feel exhausted in the morning, struggle to complete routine tasks, or feel mentally sluggish throughout the day. In contrast, normal tiredness usually resolves after rest or sleep. If fatigue is severe, doesn’t improve with rest, or is accompanied by other symptoms such as muscle weakness, unexplained weight changes, or mood disturbances, it may indicate a thyroid disorder. Health experts such as those at the Endocrine Society recommend seeing a healthcare provider for evaluation and possible thyroid function testing if persistent fatigue remains unexplained.

2. Unexplained Weight Changes

2. Unexplained Weight Changes
A digital weight scale displays changing numbers as a person tracks their body weight, reflecting both loss and gain. | Generated by Google Gemini

Both an underactive thyroid (hypothyroidism) and an overactive thyroid (hyperthyroidism) can significantly impact body weight. When thyroid function slows, metabolism decreases, leading to unexpected weight gain even if eating habits and physical activity levels remain unchanged. Conversely, an overactive thyroid accelerates metabolism, causing rapid weight loss that is not explained by increased exercise or reduced calorie intake. These changes are often more dramatic and persistent than the typical weight fluctuations that can result from dietary changes, stress, or temporary shifts in activity levels.

Normal weight variations are usually gradual and can be traced to lifestyle or nutritional factors. However, in the case of thyroid disorders, the changes tend to be more pronounced and may occur rapidly. For example, a person with hypothyroidism may notice a steady increase in weight over a few months despite maintaining the same diet, while someone with hyperthyroidism may lose weight quickly without trying. According to the American Thyroid Association, unexplained weight gain or loss should not be ignored, especially if accompanied by other symptoms like fatigue or mood changes. Monitoring and reporting these unexplained shifts to a healthcare provider can facilitate early detection and treatment of thyroid dysfunction.

3. Hair Loss or Thinning

3. Hair Loss or Thinning
Thyroid hormone imbalances disrupt hair follicle cycles, leading to diffuse, evenly distributed hair thinning.

Thyroid hormones play a crucial role in regulating the growth cycle of hair follicles. When thyroid hormone levels are imbalanced—either too high or too low—the normal cycle of hair growth, rest, and shedding is disrupted. Both hypothyroidism and hyperthyroidism can lead to diffuse hair thinning, where hair loss is spread evenly across the scalp rather than appearing in distinct patches. Unlike typical hair shedding, which most people experience daily, thyroid-related hair loss is often more noticeable and persistent.

An individual might observe increased hair on their pillow, in the shower drain, or on their hairbrush, along with overall thinning and a lack of hair volume. In severe cases, thinning can also affect the eyebrows or other body hair. According to the American Academy of Dermatology Association, this kind of hair loss may continue until the underlying thyroid disorder is treated. If you notice ongoing, unexplained hair loss that doesn’t improve with regular hair care or dietary changes, or if it is associated with other symptoms such as fatigue or weight changes, consult a healthcare provider. Early evaluation can help address both the hair loss and its root cause.

4. Changes in Heart Rate

4. Changes in Heart Rate
A close-up of a nurse checking a patient’s pulse beside an ECG monitor displaying a steady heartbeat. | Generated by Google Gemini

The thyroid gland has a significant impact on cardiovascular health, particularly in regulating heart rate. Thyroid hormones increase or decrease the heart’s speed and force of contraction, helping to maintain a healthy rhythm. In hypothyroidism, an underactive thyroid can slow the heart rate (bradycardia), making it feel sluggish or slow. Conversely, hyperthyroidism can accelerate the heart rate (tachycardia), resulting in palpitations, pounding in the chest, or even irregular heart rhythms like atrial fibrillation.

Normal heart rate variations occur with physical activity, stress, or excitement, and these changes are temporary and resolve with rest. However, thyroid-related changes are typically persistent and may be unrelated to exertion. For example, someone with hyperthyroidism may notice their heart racing while at rest or experience frequent episodes of skipped beats. According to the American Thyroid Association, persistent palpitations, unexplained rapid or slow heart rates, or new irregular rhythms warrant prompt medical evaluation. These symptoms should not be overlooked, as unmanaged thyroid dysfunction can increase the risk of serious heart problems, including heart failure and stroke. Early screening and treatment can help restore normal heart rhythm and protect cardiovascular health.

5. Sensitivity to Cold or Heat

5. Sensitivity to Cold or Heat
Thyroid hormones regulate metabolism, affecting body temperature sensitivity in both hypothyroidism and hyperthyroidism.

Thyroid hormones are essential in regulating the body’s metabolism, which in turn influences how the body generates and manages heat. In hypothyroidism, when thyroid hormone production is low, the body’s metabolic processes slow down, leading to an increased sensitivity to cold. Individuals may find themselves feeling chilly even in warm environments, needing extra layers, or having cold hands and feet. On the other hand, hyperthyroidism causes the metabolism to speed up, making people more prone to heat intolerance. They may sweat excessively, feel overheated in normal temperatures, or have difficulty tolerating hot weather.

Real-life examples include someone with hypothyroidism who shivers while others are comfortable or must use a space heater in mild conditions. Conversely, an individual with hyperthyroidism may frequently seek out cooler environments, avoid outdoor activities in the summer, or feel flushed and sweaty without explanation. According to the EndocrineWeb, unusual sensitivity to temperature changes—especially if it is new, persistent, or occurs alongside other symptoms such as fatigue or weight changes—should be monitored. Tracking these symptoms and sharing them with a healthcare provider can aid in the early identification of thyroid problems.

6. Dry Skin and Brittle Nails

6. Dry Skin and Brittle Nails
A close-up of a hand reveals dry, flaky skin and brittle nails, highlighting the need for gentle care. | Generated by Google Gemini

Thyroid hormones help regulate the growth and turnover of skin cells and play a vital role in maintaining the moisture, texture, and integrity of both skin and nails. In hypothyroidism, decreased hormone levels slow down skin cell regeneration, often resulting in dry, rough, or flaky skin that doesn’t respond well to regular moisturizers. Nails may become brittle, develop ridges, or break easily. Hyperthyroidism can also affect skin and nails, sometimes causing thinning skin or unusually soft, easily split nails.

Ordinary dryness or brittle nails are commonly linked to environmental factors, such as frequent hand washing, seasonal changes, or exposure to harsh chemicals. These cases usually improve with moisturizing creams, dietary adjustments, or protective measures. However, dryness and brittleness from thyroid dysfunction tend to be persistent and widespread, affecting areas like the elbows, heels, and scalp, and may be accompanied by hair thinning or other systemic symptoms. According to the American Academy of Dermatology Association, if you notice ongoing changes in your skin or nails despite good care, especially when paired with fatigue, weight changes, or other symptoms, it’s wise to seek medical advice and consider thyroid testing.

7. Constipation or Diarrhea

7. Constipation or Diarrhea
Clutching his stomach in pain, a man hurries toward the bathroom, highlighting the struggles of digestive discomfort. | Generated by Google Gemini

Thyroid hormones influence the speed at which the digestive system operates by affecting the muscle contractions of the gastrointestinal tract. In hypothyroidism, reduced hormone levels slow down these contractions, often leading to persistent constipation. Stools become infrequent or difficult to pass, and individuals may experience bloating or abdominal discomfort. In contrast, hyperthyroidism speeds up digestive processes, resulting in frequent bowel movements or even chronic diarrhea, sometimes accompanied by cramping and urgency.

Typical changes in bowel habits are usually short-lived, often linked to dietary adjustments, stress, illness, or medications. They tend to resolve within a few days and don’t usually disrupt daily life. However, constipation or diarrhea related to thyroid dysfunction is more persistent, not easily explained by lifestyle factors, and may come with other symptoms such as fatigue, weight changes, or mood disturbances. According to the Harvard Health Publishing, ongoing changes in bowel habits that last for several weeks, especially if accompanied by other thyroid-related signs, warrant medical attention. Early investigation can help identify an underlying thyroid disorder and prevent complications related to prolonged digestive disruption.

8. Menstrual Irregularities

8. Menstrual Irregularities
A hand marks a date on a calendar surrounded by period tracking stickers and notes for managing female health. | Generated by Google Gemini

Thyroid hormones play a key role in regulating the reproductive system, including the menstrual cycle. When thyroid hormone levels are imbalanced, they can disrupt the normal release of reproductive hormones, causing irregularities in menstrual patterns. Hypothyroidism is often associated with heavier, more prolonged, or more frequent periods (menorrhagia), while hyperthyroidism can result in lighter, less frequent, or even absent periods (amenorrhea). These disruptions may also increase the risk of fertility issues or complications during pregnancy.

Normal menstrual variations can occur due to stress, changes in contraception, weight fluctuations, or lifestyle adjustments. Typically, these variations are short-term and stabilize within a cycle or two. However, menstrual disturbances related to thyroid dysfunction tend to be persistent and may occur alongside other symptoms, such as fatigue, hair loss, or unexplained weight changes. According to the U.S. Office on Women’s Health, women who notice significant or ongoing changes in the length, flow, or frequency of their periods should seek medical assessment. Early evaluation is especially important if menstrual irregularities are combined with other possible signs of a thyroid disorder, as timely intervention can support reproductive and overall health.

9. Mood Swings and Depression

9. Mood Swings and Depression
A woman sits alone by a window, her expression somber, reflecting the emotional weight of mood swings and mental health struggles. | Generated by Google Gemini

Thyroid hormones have a profound effect on brain function, influencing neurotransmitter activity and emotional regulation. When thyroid levels are imbalanced, this can lead to mood disturbances such as depression, anxiety, irritability, or sudden mood swings. Hypothyroidism is frequently associated with low mood, persistent sadness, and cognitive sluggishness, while hyperthyroidism can cause restlessness, nervousness, or emotional instability.

It is not uncommon for individuals to be misdiagnosed with primary depression or anxiety when, in fact, an underlying thyroid disorder is the root cause. For example, a person may seek help for persistent feelings of sadness, fatigue, and loss of interest in daily activities, only to discover after thyroid testing that hypothyroidism is responsible for their symptoms. According to the American Thyroid Association, thyroid screening should be considered when new or unexplained mood changes develop, especially if accompanied by other physical symptoms like weight changes or fatigue.

Because thyroid-related mood issues often improve with proper treatment of the underlying disorder, recognizing the connection between mental health and thyroid function is essential. If you or someone you know is experiencing persistent mood symptoms, discuss the possibility of a thyroid evaluation with a healthcare provider.

10. Muscle Weakness or Joint Pain

10. Muscle Weakness or Joint Pain
A person gently stretches their legs on a yoga mat, easing muscle and joint pain with focused movements. | Generated by Google Gemini

Thyroid hormones are essential for normal muscle and joint function, as they regulate metabolism and support tissue repair and growth. When the thyroid is underactive (hypothyroidism), muscle fibers may not receive enough stimulation, resulting in stiffness, weakness, cramps, or aches. Conversely, an overactive thyroid (hyperthyroidism) can lead to muscle breakdown, causing muscle fatigue and weakness, especially in the upper arms and thighs. Joint pain and swelling can also appear, further impacting mobility and quality of life.

It’s common for people to attribute muscle soreness to physical exertion, especially after exercise or manual labor. For example, someone might assume their persistent muscle aches are due to a new workout routine, overlooking the fact that the discomfort persists despite rest or reduced activity. According to the Arthritis Foundation, ongoing or unexplained muscle weakness, stiffness, or joint pain that doesn’t improve with conventional measures should prompt further investigation.

If these symptoms are severe, persistent, or occur alongside other signs such as fatigue, weight, or mood changes, it may indicate a thyroid disorder. Early recognition and evaluation can help address both musculoskeletal discomfort and its underlying cause.

11. Swelling in the Neck (Goiter)

11. Swelling in the Neck (Goiter)
A noticeable swelling at the base of the neck indicates an enlarged thyroid gland, commonly known as a goiter. | Generated by Google Gemini

A goiter refers to the abnormal enlargement of the thyroid gland, which is located at the base of the neck, just below the Adam’s apple. This swelling can develop in response to both underactive (hypothyroidism) and overactive (hyperthyroidism) thyroid conditions, as well as from iodine deficiency or certain autoimmune diseases like Hashimoto’s thyroiditis and Graves’ disease. The thyroid gland may become visibly enlarged, or the swelling may be noticed only during swallowing or when pressing gently on the neck.

Visually, a goiter can appear as a subtle fullness or a distinct lump at the front of the neck. In some cases, it may cause tightness, difficulty swallowing, or even changes in voice. According to the Mayo Clinic, any persistent swelling or lump in the neck should be examined by a healthcare provider to determine its cause.

While goiters are often benign, they can signal an underlying thyroid dysfunction or, more rarely, thyroid cancer. Early evaluation is crucial for appropriate management. If you notice new or increasing neck swelling, seek prompt medical attention for a thorough assessment and possible thyroid testing.

12. Hoarseness or Voice Changes

12. Hoarseness or Voice Changes
A detailed illustration of throat anatomy highlights the vocal cords, showing possible causes of hoarse voice and voice changes. | Generated by Google Gemini

The thyroid gland is situated just below the voice box (larynx) in the neck, so any enlargement—whether due to a goiter, thyroid nodules, or inflammation—can put pressure on the surrounding structures. This pressure may affect the vocal cords, resulting in hoarseness, a raspy or weak voice, or subtle changes in vocal tone. Thyroid nodules, which are small lumps within the thyroid, can also directly impact the nerves that control the voice, leading to persistent vocal alterations.

Temporary hoarseness is common and usually results from upper respiratory infections, allergies, or excessive voice use. These cases typically resolve within a few days to weeks. In contrast, hoarseness or voice changes caused by thyroid issues tend to last longer and may worsen over time, especially if associated with visible neck swelling or difficulty swallowing. According to the American Academy of Otolaryngology-Head and Neck Surgery Foundation, persistent hoarseness lasting more than two weeks should be evaluated by a healthcare provider or an ear, nose, and throat (ENT) specialist.

If you experience ongoing voice changes, particularly in combination with other thyroid-related symptoms, seek medical assessment to rule out thyroid dysfunction or other serious conditions.

13. Difficulty Swallowing or Breathing

13. Difficulty Swallowing or Breathing
A concerned woman gently touches her throat, her expression reflecting discomfort from swallowing and difficulty breathing. | Generated by Google Gemini

As the thyroid gland enlarges due to conditions like goiter or the formation of nodules, it can compress nearby structures such as the trachea (windpipe) and esophagus (food pipe). This compression may result in difficulty swallowing (dysphagia), a sensation of food sticking in the throat, or even shortness of breath, especially when lying down. In more severe cases, the airway may be narrowed, causing noisy breathing or a persistent cough.

Occasional mild throat discomfort or the sensation of a “lump in the throat” can occur with allergies, colds, or acid reflux and typically resolves within a short period. However, persistent or progressive symptoms—such as trouble swallowing solids or liquids, frequent choking, or unexplained shortness of breath—are signs that should not be ignored. According to the American Cancer Society, any new or worsening swallowing or breathing difficulties, especially with visible neck swelling or hoarseness, require urgent medical evaluation.

Prompt attention can help identify underlying thyroid conditions and rule out more serious issues, such as thyroid cancer. Early diagnosis is key to effective treatment and preventing complications.

14. Puffy Face or Eyes

14. Puffy Face or Eyes
Facial puffiness and periorbital swelling as signs of thyroid dysfunction, including hypothyroidism and Graves’ diseas…

Thyroid dysfunction, especially hypothyroidism, can lead to fluid accumulation in the tissues, resulting in facial puffiness or swelling around the eyes. This occurs when low thyroid hormone levels slow the metabolism and affect the body’s ability to regulate salt and water balance. Hyperthyroidism, particularly in Graves’ disease, may also cause characteristic eye changes, including bulging or swelling, due to inflammation and tissue buildup behind the eyes.

Normal facial puffiness is common after waking up in the morning, following high salt intake, or after crying, and usually subsides within a short time as the body rebalances fluids. In contrast, puffiness associated with thyroid disorders tends to persist throughout the day and may gradually worsen. It is often accompanied by other symptoms such as fatigue, dry skin, or unexplained weight changes. According to the EndocrineWeb, persistent swelling of the face or around the eyes—especially when not linked to temporary causes—should prompt further evaluation.

If you notice ongoing or worsening facial puffiness, particularly if it is combined with other signs of thyroid dysfunction, consult a healthcare provider for assessment and possible thyroid function testing.

15. High Cholesterol Levels

15. High Cholesterol Levels
Hypothyroidism impairs cholesterol clearance, raising LDL levels and increasing long-term cardiovascular risk.

There is a well-established connection between hypothyroidism and elevated cholesterol levels. Thyroid hormones help regulate how the body processes and eliminates cholesterol from the bloodstream. When hormone levels are low, as in hypothyroidism, the liver is less efficient at clearing low-density lipoprotein (LDL) cholesterol, often leading to higher total and LDL cholesterol levels. Over time, this can increase the risk of cardiovascular disease, even in individuals who otherwise follow a healthy lifestyle.

Typically, high cholesterol is attributed to factors like diet, lack of exercise, or genetics. However, if a person maintains a balanced diet and regular physical activity but still develops high cholesterol, an underlying thyroid disorder may be to blame. For example, someone might have persistently elevated cholesterol levels despite dietary changes and statin therapy, only to discover after testing that hypothyroidism is the root cause. According to the Cleveland Clinic, unexplained increases in cholesterol should prompt a thyroid function test.

If you or your healthcare provider notice an unexpected rise in cholesterol levels—especially if accompanied by other potential thyroid symptoms—it is important to assess thyroid health to guide effective treatment and reduce cardiovascular risks.

16. Decreased Libido

16. Decreased Libido
Thyroid hormone imbalances disrupt sex hormones and energy, leading to decreased libido and reproductive challenges.

Thyroid hormones influence many aspects of reproductive health, including the regulation of sex hormones and overall energy levels. Both hypothyroidism and hyperthyroidism can disrupt the delicate hormonal balance required for a healthy sex drive. Low thyroid hormone levels may cause fatigue, depression, and other symptoms that directly or indirectly lower libido. Additionally, hypothyroidism can reduce levels of sex hormones such as estrogen and testosterone, further diminishing sexual desire in both men and women. Hyperthyroidism, with its associated anxiety and restlessness, may also negatively affect interest in sexual activity.

Temporary declines in libido are common during periods of stress, illness, or significant life changes, and typically resolve when circumstances improve. In contrast, a persistently low sex drive that does not improve with stress reduction, rest, or relationship changes may indicate an underlying medical issue such as a thyroid disorder. According to the Hormone Health Network, ongoing reductions in sexual desire—especially when accompanied by other symptoms such as fatigue, weight change, or mood disturbances—should prompt a discussion with a healthcare provider.

Timely evaluation can help identify thyroid-related causes of decreased libido and guide appropriate treatment to restore hormonal balance and improve quality of life.

17. Memory Problems or Brain Fog

17. Memory Problems or Brain Fog
A perplexed person sits with furrowed brows, surrounded by swirling clouds that symbolize brain fog and memory lapses. | Generated by Google Gemini

Thyroid hormones are essential for optimal brain function, affecting concentration, memory, and mental clarity. When thyroid hormone levels are imbalanced, both hypothyroidism and hyperthyroidism can lead to cognitive symptoms such as forgetfulness, difficulty concentrating, and a sensation often described as “brain fog.” These symptoms may be subtle at first but can become more pronounced over time, impacting work performance, learning, and daily decision-making.

It’s common for mild forgetfulness to be attributed to aging, stress, or lack of sleep. For example, someone might find themselves struggling to remember appointments, misplacing items, or feeling mentally sluggish and blame it on a busy schedule or multitasking. However, when memory lapses or mental cloudiness persist despite adequate rest and stress management, thyroid dysfunction may be at fault. According to the American Thyroid Association, ongoing cognitive difficulties—especially when accompanied by other thyroid-related symptoms such as fatigue, mood changes, or weight fluctuations—should prompt thyroid function testing.

Recognizing the link between cognitive function and thyroid health can lead to earlier diagnosis and treatment, helping to restore mental sharpness and prevent long-term complications.

18. Tremors or Shakiness

18. Tremors or Shakiness
A close-up of hands trembling slightly, highlighting the visible effects of a nervous system disorder on daily life. | Generated by Google Gemini

Excess thyroid hormones, as seen in hyperthyroidism, can overstimulate the nervous system and muscles, leading to symptoms such as tremors or shakiness. These tremors typically appear as fine, rapid movements of the hands and fingers, even when at rest. The heightened metabolic state caused by too much thyroid hormone can also result in feelings of nervousness, irritability, and an increased heart rate, further amplifying the sense of physical instability.

While hand tremors are sometimes caused by temporary factors like excessive caffeine consumption, anxiety, or fatigue, these episodes are usually short-lived and resolve once the trigger is removed. In contrast, thyroid-related tremors are persistent and may gradually worsen if the underlying hormone imbalance is not addressed. According to the Mayo Clinic, ongoing or unexplained shakiness—especially when accompanied by weight loss, rapid heartbeat, sweating, or other symptoms of hyperthyroidism—should prompt medical evaluation.

If you experience tremors that do not improve with rest or reduction of stimulants, or if they are associated with additional symptoms of thyroid dysfunction, seeking timely medical advice is crucial for accurate diagnosis and effective treatment.

19. Increased Sweating

19. Increased Sweating
Beads of perspiration glisten on a woman’s forehead as she fans herself during a sudden hot flush. | Generated by Google Gemini

Hyperthyroidism, or an overactive thyroid, accelerates the body’s metabolic processes, causing an increase in core temperature and stimulating sweat glands. As a result, people with excess thyroid hormones often experience excessive sweating, even in cool environments or during periods of rest. This heightened perspiration is the body’s attempt to cool down, but it can become uncomfortable and disruptive to daily life.

Occasional sweating is normal during exercise, hot weather, or stressful situations. However, abnormal sweating due to thyroid dysfunction tends to be persistent, occurring at unusual times and often affecting the palms, soles, face, and torso. For example, someone might find themselves waking up drenched in sweat at night or needing to change clothes multiple times a day despite being in air-conditioned settings. According to the UK National Health Service (NHS), unexplained or profuse sweating—particularly when it develops suddenly or is accompanied by other symptoms such as weight loss, fatigue, or a racing heart—can be a red flag for hyperthyroidism.

If you notice persistent or excessive sweating without an obvious cause, it’s important to consult a healthcare provider for evaluation and potential thyroid testing.

20. Sleep Disturbances

20. Sleep Disturbances
A person lies awake in bed, tangled in rumpled sheets, staring at the ceiling in the grip of insomnia. | Generated by Google Gemini

Thyroid dysfunction can significantly impact sleep quality and patterns. Hyperthyroidism often leads to increased metabolism and heightened nervous system activity, making it difficult to fall or stay asleep. Individuals may experience insomnia, frequent awakenings, and a sense of restlessness throughout the night. Hypothyroidism, on the other hand, can cause excessive fatigue and sleepiness, yet some people may still report non-refreshing sleep or difficulty maintaining a regular sleep cycle.

Occasional sleep disturbances are common and may result from stress, changes in routine, or environmental factors. These typically resolve once the underlying trigger is addressed. In contrast, thyroid-related sleep issues are more persistent and may be accompanied by other symptoms such as anxiety, muscle weakness, or unexplained weight fluctuations. For example, someone with hyperthyroidism might lie awake for hours feeling jittery, while a person with hypothyroidism may feel tired all day yet struggle to achieve restorative sleep at night. According to Sleep Foundation, persistent or unexplained changes in sleep quality should prompt consideration of thyroid screening.

If sleep disruption continues despite good sleep hygiene, it’s important to consult a healthcare provider to explore possible thyroid involvement and receive appropriate treatment.

21. Irregular Heartbeat (Arrhythmia)

21. Irregular Heartbeat (Arrhythmia)
A heart monitor screen displays an erratic pattern, highlighting the presence of an irregular heartbeat due to arrhythmia. | Generated by Google Gemini

The thyroid gland plays a critical role in regulating the heart’s electrical system and rhythm. Both hypothyroidism and hyperthyroidism can disrupt normal cardiac function, but arrhythmias are particularly associated with excess thyroid hormones. Hyperthyroidism can cause the heart to beat irregularly, rapidly, or erratically—often manifesting as atrial fibrillation, a condition that increases the risk of stroke and heart failure. Hypothyroidism may also contribute to slow or irregular heartbeats, though less commonly.

Most people experience occasional palpitations or skipped beats due to stress, caffeine, or strenuous exercise. However, when arrhythmias arise suddenly and without clear cause, it may point to an underlying thyroid imbalance. For instance, an otherwise healthy person might notice their heart fluttering, pounding, or racing unexpectedly at rest. According to the American Heart Association, new or persistent irregular heartbeats, especially when accompanied by other symptoms like tremors, weight change, or anxiety, warrant immediate medical attention.

Prompt evaluation by a healthcare provider is crucial, as untreated thyroid-related arrhythmias can lead to serious complications. Thyroid function testing is an important step for anyone experiencing unexplained changes in heart rhythm.

22. Fertility Issues

22. Fertility Issues
A hopeful woman holds a positive pregnancy test, symbolizing a significant moment in her fertility and reproductive health journey. | Generated by Google Gemini

Thyroid hormones are essential for the normal functioning of the reproductive system in both women and men. Imbalances in thyroid function—whether hypothyroidism or hyperthyroidism—can disrupt ovulation, menstrual cycles, and sperm production, making conception more difficult. In women, hypothyroidism may lead to irregular or absent periods, anovulation (lack of egg release), or early pregnancy loss. In men, thyroid dysfunction can affect sperm quality and libido, further complicating efforts to conceive.

For example, a woman struggling to become pregnant may undergo various medical tests, only to eventually discover that undiagnosed hypothyroidism is at the root of her infertility. Once her thyroid disorder is treated and hormone levels are stabilized, her chances of conceiving often improve. According to the American Society for Reproductive Medicine, thyroid screening should be a standard part of fertility evaluations, as early intervention can have a significant positive impact on reproductive outcomes.

If you are experiencing difficulty conceiving, especially when accompanied by other symptoms such as fatigue, weight changes, or menstrual irregularities, it’s important to discuss thyroid testing with your healthcare provider as part of a comprehensive fertility workup.

23. Carpal Tunnel Syndrome

23. Carpal Tunnel Syndrome
A close-up of a hand clutching a painful wrist, illustrating discomfort from nerve compression caused by carpal tunnel syndrome. | Generated by Google Gemini

Hypothyroidism is a recognized risk factor for carpal tunnel syndrome, a condition caused by compression of the median nerve as it passes through the wrist. Low thyroid hormone levels can lead to the accumulation of mucopolysaccharides and fluid in the tissues, increasing pressure within the carpal tunnel and resulting in nerve irritation. This can cause symptoms such as numbness, tingling, weakness, and pain in the hands and fingers, which may worsen at night or during repetitive hand activities.

Classic carpal tunnel syndrome is often linked to repetitive hand use, wrist injuries, or certain medical conditions like diabetes. However, in thyroid-linked cases, symptoms may develop without clear overuse or trauma and can affect both wrists. According to the Mayo Clinic, individuals with persistent or unexplained hand and wrist symptoms, especially if accompanied by other signs of hypothyroidism such as fatigue, weight gain, or dry skin, should consider thyroid function testing as part of their evaluation.

If you experience ongoing carpal tunnel symptoms that do not improve with rest or ergonomic adjustments, consult a healthcare provider to explore the potential connection to thyroid health and determine appropriate treatment.

24. Slow Heart Rate (Bradycardia)

24. Slow Heart Rate (Bradycardia)
A digital heart monitor displays a slow pulse, highlighting the importance of monitoring bradycardia for heart health. | Generated by Google Gemini

Thyroid hormones play a crucial role in maintaining the normal pace and rhythm of the heart. In hypothyroidism, low levels of thyroid hormones can slow the heart’s electrical signals, resulting in bradycardia—a heart rate that is slower than normal. This can lead to symptoms such as fatigue, dizziness, weakness, shortness of breath, or even fainting. In severe cases, bradycardia can compromise the heart’s ability to pump blood effectively, increasing the risk of heart failure and other complications.

Bradycardia can sometimes occur in well-trained athletes due to their high cardiovascular fitness, but this is generally not associated with symptoms and is considered normal. In contrast, unexplained bradycardia in someone without a history of intense physical training, or accompanied by symptoms, should raise suspicion for an underlying medical condition such as hypothyroidism. For example, a person may notice their pulse is consistently below 60 beats per minute, along with sluggishness or lightheadedness. According to the Cedars-Sinai Medical Center, persistent slow heart rate, particularly with other symptoms of hypothyroidism, warrants cardiac and thyroid evaluation.

Early identification and treatment of thyroid-related bradycardia can improve heart function and overall health outcomes.

25. Anxiety or Nervousness

25. Anxiety or Nervousness
A young woman sits with her hands clasped tightly, her anxious expression reflecting the weight of her thoughts. | Generated by Google Gemini

Thyroid hormones significantly influence the brain’s neurotransmitters, which regulate mood and emotional responses. Excess thyroid hormone, as seen in hyperthyroidism, can overstimulate the nervous system, resulting in persistent anxiety, irritability, restlessness, or a constant sense of nervousness. These feelings often occur alongside physical symptoms such as a racing heart, tremors, sweating, or trouble sleeping, amplifying the sense of unease.

Situational anxiety is a normal reaction to life stressors such as work deadlines, public speaking, or personal challenges, and typically resolves when the situation improves or with standard coping strategies. However, thyroid-related anxiety tends to be persistent, less responsive to relaxation techniques, and sometimes appears without any clear trigger. For example, someone may feel constantly “on edge” or unable to relax, despite a lack of external stressors. According to the Psychology Today, anxiety that resists usual interventions, especially when accompanied by other symptoms like weight loss, palpitations, or changes in appetite, should prompt a medical evaluation.

If you experience ongoing anxiety or nervousness that does not improve with typical approaches, discussing a thyroid screening with your healthcare provider can help uncover or rule out an underlying hormonal imbalance.

26. Enlarged Tongue

26. Enlarged Tongue
A close-up view of a mouth exam reveals a noticeably enlarged tongue, a classic sign of macroglossia. | Generated by Google Gemini

Hypothyroidism can lead to a condition called macroglossia, or an enlarged tongue. This occurs due to the accumulation of mucopolysaccharides and fluid within the tissues, a hallmark of untreated or severe hypothyroidism. The swollen tongue may appear thick, scalloped along the edges from pressing against the teeth, and can sometimes cause speech difficulties, snoring, or even trouble swallowing and breathing. Macroglossia is more commonly seen in longstanding, untreated cases and can be especially noticeable in the morning or after periods of inactivity.

Ordinary mild tongue swelling can occur after trauma, allergic reactions, or dehydration, and usually resolves quickly with appropriate care. In contrast, thyroid-related enlargement tends to be persistent and may be accompanied by other signs such as dry skin, fatigue, hoarseness, or facial puffiness. For example, a person might struggle with articulation or notice dental impressions along the sides of their tongue despite good oral hygiene. According to the National Institutes of Health (NIH), macroglossia should prompt further evaluation for underlying systemic causes, including thyroid dysfunction.

If you or someone you know has a persistently enlarged tongue along with other symptoms of hypothyroidism, consult a healthcare provider for comprehensive thyroid assessment.

27. Paleness or Yellowing of Skin

Thyroid disorders can cause noticeable changes in skin color, including paleness or a yellowish tint. In hypothyroidism, slowed metabolism and reduced circulation may lead to a pale, cool complexion. Additionally, impaired conversion of beta-carotene to vitamin A can result in carotene buildup, giving the skin a subtle yellow hue—most apparent on the palms and soles. Hyperthyroidism, while less likely to cause yellowing, may cause skin flushing or increased redness due to heightened blood flow.

Normal skin color variations often occur with changes in temperature, physical activity, or temporary conditions like mild dehydration or stress, and typically resolve on their own. In contrast, persistent paleness or yellowing unrelated to dietary changes (such as eating large amounts of carrots) may indicate an underlying thyroid issue. For example, someone might notice their skin appears unusually pale even after spending time outdoors, or friends may comment on a yellowish tint to their hands or feet. According to the DermNet NZ, ongoing skin discoloration—especially with other symptoms like fatigue, dry skin, or swelling—warrants further investigation.

If you observe lasting changes in your skin tone, it’s important to consult a healthcare provider and consider thyroid function testing.

28. Increased Appetite

28. Increased Appetite
Increased appetite and frequent hunger driven by accelerated metabolism in hyperthyroidism.

Hyperthyroidism, or an overactive thyroid, can significantly increase appetite. Elevated thyroid hormone levels accelerate metabolic rate and energy expenditure, prompting the body to demand more calories in an effort to keep up. As a result, individuals may experience constant hunger or the urge to eat larger, more frequent meals—even if they are not engaging in more physical activity. Paradoxically, despite eating more, many people with hyperthyroidism continue to lose weight due to the rapid metabolism.

Normal fluctuations in appetite can occur in response to stress, emotional changes, or temporary increases in activity and generally resolve as circumstances change. For example, stress-related hunger might cause someone to snack more during a busy week, but this usually subsides once stress levels decrease. In contrast, a thyroid-related increase in appetite tends to be persistent and is often accompanied by other symptoms such as weight loss, sweating, anxiety, or tremors. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), ongoing, unexplained hunger should prompt evaluation for possible hormonal causes.

If you notice a sustained increase in appetite along with other signs of thyroid dysfunction, consult a healthcare provider for assessment and potential thyroid testing.

29. Decreased Appetite

29. Decreased Appetite
A barely touched meal sits on a plate, untouched silverware nearby, hinting at a sudden loss of appetite. | Generated by Google Gemini

Hypothyroidism, or an underactive thyroid, often leads to a decrease in appetite due to the slowing of metabolic processes. When thyroid hormone levels are low, digestive activity diminishes, and the body’s demand for energy drops, resulting in reduced feelings of hunger. Individuals may find themselves eating less than usual, feeling full quickly, or simply having little interest in food. Despite the lower calorie intake, weight gain is still common because metabolism slows and the body retains fluids and fat more readily.

Temporary appetite loss can be caused by stress, illness, or dietary changes and usually improves once the underlying situation resolves. For instance, someone might eat less during a bout of the flu or during a particularly stressful week at work. However, when a decreased appetite persists for weeks or months and is accompanied by other symptoms—such as fatigue, constipation, dry skin, or unexplained weight gain—it may signal a thyroid disorder. According to Cleveland Clinic, ongoing lack of appetite should be evaluated when it occurs alongside other hypothyroid symptoms.

If you or someone you know experiences persistent low appetite and other signs of thyroid imbalance, it’s important to seek medical advice and consider thyroid function testing.

30. Irregular Menstrual Flow

30. Irregular Menstrual Flow
Thyroid hormone imbalances disrupt menstrual cycles by altering estrogen and progesterone levels.

Thyroid hormones are closely tied to the regulation of the menstrual cycle, and imbalances can lead to significant changes in menstrual flow. Hypothyroidism often results in heavier, more prolonged periods (menorrhagia), while hyperthyroidism can cause lighter, shorter, or even missed periods (oligomenorrhea or amenorrhea). These disruptions occur because thyroid hormones affect the levels of reproductive hormones like estrogen and progesterone, which control the growth and shedding of the uterine lining.

Normal menstrual flow can vary somewhat from cycle to cycle due to stress, changes in weight, exercise routines, or age-related hormonal shifts. However, thyroid-related menstrual changes tend to be more dramatic and persistent. For example, a woman might experience periods that become suddenly much heavier and longer, requiring frequent changes of sanitary products, or, conversely, notice her periods becoming very light or stopping altogether. According to the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), tracking menstrual changes and other symptoms over time is important for early detection of thyroid disorders.

If you notice significant or ongoing changes in menstrual flow along with symptoms like fatigue, weight changes, or hair loss, consult a healthcare provider and consider thyroid testing.

31. Problems with Balance or Coordination

31. Problems with Balance or Coordination
A woman cautiously walks down a hallway, her arms outstretched for balance as she struggles with unsteady steps. | Generated by Google Gemini

Thyroid disorders, particularly when severe or long-standing, can impact the nervous system and lead to issues with balance and coordination. Both hypothyroidism and hyperthyroidism can affect nerve function—hypothyroidism by slowing nerve conduction and hyperthyroidism by increasing neuromuscular excitability. This may result in symptoms such as unsteadiness, a tendency to stumble, difficulty with fine motor tasks, or a general sense of being off-balance.

Normal episodes of dizziness or clumsiness are often linked to factors like fatigue, dehydration, or a temporary illness and typically resolve with rest or hydration. In contrast, thyroid-related balance problems are more persistent and may gradually worsen, especially if other symptoms like muscle weakness, tingling, or numbness are present. For example, someone might notice increasing difficulty walking on uneven surfaces or trouble with activities that require coordination, such as buttoning a shirt. According to the Merck Manual, persistent balance or coordination problems, especially when accompanied by other signs of thyroid dysfunction, warrant further medical investigation.

If you experience ongoing issues with balance or coordination, it is important to consult a healthcare provider for a comprehensive evaluation, including possible thyroid function testing.

32. Shortness of Breath

32. Shortness of Breath
Thyroid disorders may cause shortness of breath by affecting lung capacity, muscle strength, or airway.

Thyroid disorders can affect lung and muscle function, sometimes leading to unexplained shortness of breath. In hypothyroidism, weakened respiratory muscles and fluid retention may reduce lung capacity, making it harder to take deep breaths. Hyperthyroidism, on the other hand, can cause rapid metabolism and increased oxygen demand, occasionally resulting in a sense of breathlessness or rapid breathing. Additionally, an enlarged thyroid (goiter) can physically compress the windpipe, further impairing airflow.

Normal shortness of breath is usually temporary and occurs after exercise, climbing stairs, or during periods of anxiety, resolving quickly with rest. In contrast, thyroid-related breathlessness is often persistent, may worsen with minimal activity, and might be accompanied by other symptoms such as fatigue, swelling, or chest discomfort. For example, someone may find themselves winded after routine activities like walking across a room or talking, despite being otherwise healthy. According to the American Thyroid Association, unexplained, ongoing shortness of breath—especially when coupled with neck swelling or other thyroid symptoms—should prompt immediate medical evaluation.

If you notice persistent breathlessness without a clear cause, consult a healthcare provider promptly for assessment and possible thyroid function testing.

33. Heavy or Prolonged Menstrual Bleeding

33. Heavy or Prolonged Menstrual Bleeding
A woman sits thoughtfully on her bed with a hot water bottle, concerned about heavy, prolonged menstrual bleeding. | Generated by Google Gemini

Hypothyroidism is a well-known cause of heavy or prolonged menstrual bleeding, medically referred to as menorrhagia. Low levels of thyroid hormones can disrupt the delicate balance of reproductive hormones, leading to excessive growth and delayed shedding of the uterine lining. As a result, periods may last longer than usual or require frequent changes of pads or tampons, sometimes even interfering with daily activities or causing significant fatigue due to blood loss.

While it’s normal for menstrual flow to fluctuate slightly from cycle to cycle, consistently heavy or prolonged bleeding is not typical and may signal an underlying thyroid disorder. For example, a woman who previously experienced regular, manageable periods might suddenly find herself needing to change sanitary protection every couple of hours or passing large blood clots. According to the American College of Obstetricians and Gynecologists (ACOG), women experiencing ongoing heavy or prolonged periods—especially in combination with other symptoms like fatigue, weight gain, or cold intolerance—should seek medical advice.

Timely evaluation can help determine whether hypothyroidism or another condition is responsible and guide appropriate management to prevent complications such as anemia.

34. Light or Missed Periods

34. Light or Missed Periods
A hand marks a calendar with question marks and circles, highlighting confusion over a missed or unusually light period. | Generated by Google Gemini

Thyroid dysfunction, particularly hyperthyroidism, can lead to hypomenorrhea (light periods) or amenorrhea (missed periods). Excess thyroid hormones disrupt the balance of reproductive hormones, interfering with ovulation and the normal menstrual cycle. As a result, periods may become very light, infrequent, or stop altogether. This can also occur in cases of severe hypothyroidism, where hormonal imbalances suppress the signaling required for regular menstruation.

It’s not unusual to miss an occasional period due to stress, significant weight changes, intense exercise, or transitional life phases such as adolescence or perimenopause. These instances are typically temporary and resolve with lifestyle adjustments or over time. However, when periods are consistently lighter than usual or absent for several months, a thyroid disorder may be the underlying cause. For example, a woman might go months without menstruating or notice a drastic reduction in menstrual flow without changes in contraceptive use or physical activity. According to Women’s Health.gov, tracking menstrual patterns and associated symptoms is important for early detection of thyroid issues.

If you experience ongoing changes in your menstrual cycle, it’s important to record the pattern and consult a healthcare provider for evaluation and thyroid screening if needed.

35. High Blood Pressure

35. High Blood Pressure
A healthcare professional checks a patient’s arm with a blood pressure cuff, monitoring for signs of hypertension. | Generated by Google Gemini

Thyroid dysfunction can significantly impact blood pressure regulation. Both hyperthyroidism and hypothyroidism can contribute to high blood pressure (hypertension), though the mechanisms differ. Hyperthyroidism increases heart rate and cardiac output, causing blood vessels to constrict and elevating systolic pressure. Hypothyroidism, on the other hand, can stiffen blood vessels and affect kidney function, leading to increased diastolic pressure. Over time, these changes place extra strain on the cardiovascular system and may increase the risk of heart disease or stroke.

Most cases of hypertension are managed with lifestyle modifications and medication. However, when high blood pressure is resistant to standard treatments or occurs in individuals without typical risk factors, an underlying thyroid disorder should be considered. For example, someone may follow a low-salt diet, exercise regularly, and take prescribed medications, but still struggle to achieve normal blood pressure readings. According to the American Heart Association, unexplained or difficult-to-control hypertension warrants thyroid function testing.

If you have persistent or resistant high blood pressure, especially in conjunction with symptoms like fatigue, weight changes, or palpitations, it’s essential to discuss thyroid screening with your healthcare provider for comprehensive management.

36. Low Blood Pressure

36. Low Blood Pressure
Advanced hypothyroidism may cause low blood pressure, leading to dizziness, fatigue, and cold extremities.

While less common than high blood pressure, low blood pressure (hypotension) can also be associated with thyroid dysfunction, particularly in cases of advanced hypothyroidism. Insufficient thyroid hormone slows the heart rate, reduces cardiac output, and leads to less forceful blood flow through the arteries. This can cause symptoms such as dizziness, fainting, fatigue, weakness, and cold extremities. In severe cases, hypothyroidism may even lead to dangerously low blood pressure and shock, especially if left untreated.

Low blood pressure is often seen in healthy individuals, particularly athletes, and may also result from dehydration, blood loss, certain medications, or acute illness. These causes are typically identifiable and resolve with appropriate intervention. In contrast, thyroid-related hypotension is generally persistent and may be accompanied by other signs of hypothyroidism, such as dry skin, constipation, weight gain, or intolerance to cold. For example, a person might notice frequent lightheadedness upon standing or experience unexplained fatigue despite adequate hydration and nutrition. According to National Center for Biotechnology Information (NCBI), persistent low blood pressure should prompt evaluation for potential endocrine causes, including hypothyroidism.

If you experience ongoing low blood pressure with other symptoms suggestive of thyroid dysfunction, consult your healthcare provider for a thorough assessment and possible thyroid testing.

37. Eye Bulging (Exophthalmos)

37. Eye Bulging (Exophthalmos)
A close-up view of a person with noticeable eye bulging, a classic sign of thyroid eye disease (exophthalmos). | Generated by Google Gemini

Eye bulging, medically termed exophthalmos, is a hallmark feature of Graves’ disease—a form of hyperthyroidism caused by an autoimmune reaction. In this condition, the immune system attacks tissues around the eyes, leading to inflammation, swelling, and the buildup of tissue and fat behind the eyeballs. This pressure pushes the eyes forward, causing them to appear prominent or bulging. Additional symptoms may include eye dryness, irritation, double vision, or difficulty closing the eyelids completely.

For example, a patient may notice that friends or family comment on a “staring” appearance, or they may start struggling with excessive tearing, gritty sensations, or sensitivity to light. These changes can develop gradually or suddenly, and are often accompanied by other symptoms of hyperthyroidism, such as weight loss, tremors, or rapid heartbeat. According to the American Academy of Ophthalmology, new or worsening eye bulging should prompt urgent referral to an ophthalmologist or endocrinologist for specialized evaluation and management.

Early intervention is crucial in Graves’ eye disease to prevent complications such as vision loss, corneal damage, or optic nerve compression. If you or someone you know develops exophthalmos, seek prompt medical attention.

38. Difficulty Concentrating

38. Difficulty Concentrating
A young woman sits at her desk, resting her head in her hands as she struggles to concentrate on her work. | Generated by Google Gemini

Hypothyroidism often leads to cognitive slowing, making it hard to concentrate, process information, or stay focused on tasks. This phenomenon, sometimes called “mental fog,” occurs because low thyroid hormone levels reduce energy delivery to brain cells, impairing memory, attention, and mental clarity. People with hypothyroidism may find it difficult to follow conversations, complete work assignments, or make decisions, even if they previously excelled in these areas.

Typical distraction is often temporary and related to stress, fatigue, multitasking, or environmental interruptions. For instance, it’s normal to lose focus during a busy day or when lacking sleep, but attention usually returns with rest or reduced distractions. In contrast, hypothyroidism-related concentration problems persist despite adequate sleep and stress management, and may be accompanied by other symptoms such as fatigue, depression, or weight gain. According to the American Thyroid Association, ongoing cognitive difficulties—especially if new or worsening—should raise suspicion for thyroid dysfunction.

If you notice persistent problems with concentration, memory, or mental clarity, and these issues are not explained by lifestyle factors, consult your healthcare provider for a comprehensive assessment, including a thyroid function test.

39. Decreased Sweating

39. Decreased Sweating
A close-up of parched, flaky skin highlights the effects of reduced sweating and the importance of hydration for skin health. | Generated by Google Gemini

Hypothyroidism, or an underactive thyroid, can lead to decreased sweating due to the slowing of metabolic processes. Thyroid hormones are essential for stimulating sweat gland activity, so a deficiency reduces the body’s ability to produce sweat. As a result, individuals may notice they barely perspire during exercise, in hot weather, or even under stress. This lack of sweating can also contribute to dry, rough, or flaky skin—a common symptom in those with thyroid dysfunction.

Normally, sweat production varies based on temperature, activity level, and individual differences. Some people naturally sweat less than others, and minor fluctuations are generally not a cause for concern. However, a noticeable reduction in sweating—especially if it is a new symptom and occurs alongside other signs such as fatigue, weight gain, or sensitivity to cold—may indicate hypothyroidism. For example, someone who used to sweat moderately during workouts might suddenly find their skin remains dry, even after intense physical activity. According to the National Institutes of Health (NIH), persistent decreased sweating should be monitored in the context of other hypothyroid symptoms.

If you experience a significant decrease in sweating along with other signs of thyroid dysfunction, consult a healthcare provider to discuss the need for thyroid testing.

40. Restlessness

40. Restlessness
A young woman sits at her desk, tapping her fingers and glancing around with a restless, anxious energy. | Generated by Google Gemini

Hyperthyroidism, or an overactive thyroid, frequently results in feelings of restlessness and agitation. Elevated thyroid hormone levels accelerate the body’s metabolic and nervous system activity, making it difficult to relax or stay still. People with hyperthyroidism often describe a constant urge to move, fidget, or pace, and may struggle to sit through meetings, watch television, or even fall asleep at night. This inner agitation is often accompanied by other symptoms such as anxiety, tremors, rapid heartbeat, or increased sweating.

Occasional restlessness is common during periods of excitement, anticipation, or stress and usually resolves when the triggering event passes. In contrast, thyroid-related restlessness is persistent and can significantly disrupt daily routines and relationships. For example, a person who was previously calm may become noticeably impatient, unable to read a book or concentrate on quiet tasks, and friends or family may remark on their newfound jitteriness. According to the MSD Manual, uncharacteristic or ongoing agitation should prompt consideration of an underlying medical cause, including thyroid dysfunction.

If you or someone you know is experiencing unexplained restlessness or agitation, it’s important to seek a medical evaluation that includes thyroid function testing to identify or rule out hyperthyroidism.

41. Thin, Fragile Skin

41. Thin, Fragile Skin
Delicate, translucent skin on elderly hands reveals the gentle fragility that comes with age and experience. | Generated by Google Gemini

Thyroid dysfunction, particularly hyperthyroidism, can cause noticeable changes to the skin’s integrity. Excess thyroid hormones accelerate metabolic processes and can lead to thinning of the skin, making it appear shiny, delicate, and more prone to bruising or tearing. The skin may also become unusually smooth, and minor injuries can result in significant wounds or slow healing. In hypothyroidism, skin can become rough, dry, and scaly, but thinning and fragility are more often linked to an overactive thyroid.

Normal aging naturally leads to some degree of skin thinning, increased dryness, and reduced elasticity. However, these changes typically develop gradually over many years. In contrast, thyroid-related thinning of the skin can occur more rapidly and is often accompanied by other symptoms such as hair loss, increased sweating, or changes in nail health. For example, a person may notice new bruises or scrapes appearing easily, or their skin may tear with minor bumps. According to the DermNet NZ, sudden or pronounced skin changes—especially when accompanied by other signs of thyroid dysfunction—should be investigated by a healthcare provider.

If you experience rapid changes in skin texture, fragility, or healing, consider thyroid evaluation as part of your overall assessment.

42. Increased Frequency of Bowel Movements

42. Increased Frequency of Bowel Movements
A person sits on a toilet in a modern bathroom, holding their stomach, hinting at frequent digestive issues. | Generated by Google Gemini

Thyroid hormones play a crucial role in regulating gastrointestinal (GI) motility. In hyperthyroidism, excess thyroid hormone speeds up the digestive tract, often resulting in more frequent bowel movements or even diarrhea. This increased motility means that food passes through the intestines more quickly, sometimes preventing proper absorption of nutrients and leading to loose stools. People with an overactive thyroid may find themselves needing to use the bathroom several times a day, regardless of dietary changes or stress levels.

Normal variations in bowel habits can occur with dietary adjustments, minor illnesses, or temporary stress, and these changes typically resolve within a few days. In contrast, thyroid-related increases in bowel frequency are persistent and may be accompanied by other symptoms like weight loss, tremors, or increased appetite. For example, someone who has always had regular daily bowel movements might suddenly start going three or four times a day for weeks, despite no obvious changes in lifestyle. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), ongoing changes in bowel habits should prompt consideration of underlying thyroid dysfunction.

If you notice a sustained increase in the frequency of your bowel movements, especially with other thyroid-related symptoms, consult a healthcare provider for a thorough evaluation.

43. Irregular Sleep-Wake Cycles

43. Irregular Sleep-Wake Cycles
A digital alarm clock sits beside a restless sleeper, highlighting the struggle of disrupted sleep cycles from a sleep disorder. | Generated by Google Gemini

Thyroid disorders can disrupt the body’s natural circadian rhythms, leading to irregular sleep-wake cycles. Both hypothyroidism and hyperthyroidism affect hormone production and neurotransmitter balance, which are critical for maintaining a stable sleep pattern. Hyperthyroidism may cause difficulty falling asleep, frequent awakenings, or early morning waking, while hypothyroidism can lead to excessive sleepiness, trouble waking up, or fragmented sleep. These disruptions often result in a mismatch between desired and actual sleep times, leaving individuals feeling fatigued or groggy during the day.

Occasional disturbances in sleep-wake cycles are common with jet lag, shift work, stress, or lifestyle changes, and usually resolve with routine adjustments. However, persistent circadian disruptions despite practicing good sleep hygiene may indicate an underlying thyroid issue. For example, a person may find themselves staying awake until the early hours, then struggling to wake up for work, or experiencing unpredictable periods of extreme sleepiness. The Sleep Foundation recommends keeping a sleep diary to track bedtime, wake time, and sleep quality over several weeks.

If you experience ongoing irregularities in your sleep-wake cycle along with other thyroid-related symptoms, share your sleep diary with your healthcare provider and consider thyroid testing for a comprehensive evaluation.

44. Unusual Sensitivity to Medication

44. Unusual Sensitivity to Medication
A pharmacist carefully selects pills from a shelf, highlighting the importance of medication sensitivity in personalized care. | Generated by Google Gemini

Thyroid dysfunction can significantly influence how the body processes and responds to medications. Both hypothyroidism and hyperthyroidism alter liver enzyme activity and kidney function, impacting the absorption, metabolism, and clearance of various drugs. As a result, individuals with thyroid disorders may experience exaggerated or unexpected side effects from medications, even at standard doses. This can include increased drowsiness, palpitations, digestive upset, or more severe reactions. In some cases, medications that were previously well-tolerated may suddenly cause problems as thyroid function changes.

Typical medication side effects are usually predictable, dose-dependent, and listed in drug information guides. Most people experience mild or manageable effects that resolve with continued use or dose adjustment. However, when side effects are unusually strong, persistent, or develop after a change in thyroid status, an underlying thyroid imbalance could be a contributing factor. For example, someone with undiagnosed hypothyroidism might become excessively sedated by common sleeping aids, or a person with hyperthyroidism may develop rapid heartbeat from medications that normally wouldn’t cause this issue. According to NIH, unusual drug sensitivity warrants further investigation.

If you notice unexpected or severe medication reactions, discuss your symptoms and thyroid history with your healthcare provider to ensure safe and effective treatment.

45. Delayed Reflexes

45. Delayed Reflexes
A doctor gently taps a patient’s knee with a reflex hammer during a routine neurological exam. | Generated by Google Gemini

Hypothyroidism can significantly slow neuromuscular responses, resulting in noticeably delayed reflexes. Thyroid hormones are essential for the normal functioning of nerves and muscles, and when levels are low, the transmission of signals from nerves to muscles becomes sluggish. This is often observed by healthcare providers during neurological examinations, where the relaxation phase of deep tendon reflexes—such as the knee-jerk or ankle-jerk response—is prolonged. Patients may also experience general muscle stiffness, sluggishness, or a feeling of heaviness in their limbs.

In everyday life, delayed reflexes may not be immediately apparent but can manifest as slower reaction times, clumsiness, or difficulty performing tasks that require quick movements. For example, a person might notice they are slower to catch a falling object, react while driving, or recover from tripping. While mild reflex changes can occur with aging or fatigue, persistent and pronounced delays are not typical. According to the National Center for Biotechnology Information (NCBI), delayed reflexes are a classic but often overlooked sign of hypothyroidism.

If you or your healthcare provider notice delayed reflexes or experience persistent muscle sluggishness, a neurological evaluation and thyroid function testing are recommended to determine the underlying cause and initiate appropriate treatment.

46. Numbness or Tingling in Extremities

46. Numbness or Tingling in Extremities
Long-standing hypothyroidism may cause peripheral neuropathy, leading to numbness, tingling, and nerve dysfunction.

Thyroid dysfunction, especially long-standing hypothyroidism, can contribute to peripheral neuropathy—damage or dysfunction of the nerves outside the brain and spinal cord. This condition often manifests as numbness, tingling, or a “pins and needles” sensation in the hands, feet, arms, or legs. Low thyroid hormone levels can lead to fluid retention and tissue swelling, which may compress nerves and disrupt normal nerve signaling. Over time, untreated hypothyroidism can result in chronic nerve impairment, leading to persistent sensory changes or even weakness.

Temporary numbness or tingling is common when pressure is applied to a nerve—for example, after sitting in one position for too long or sleeping on an arm. These sensations typically resolve quickly once movement resumes. In contrast, thyroid-related neuropathy tends to be ongoing, may worsen over time, and is often accompanied by other symptoms such as muscle weakness, fatigue, or skin changes. According to the American Thyroid Association, persistent numbness or tingling is a warning sign that should not be ignored.

If you notice ongoing or unexplained numbness and tingling in your extremities, especially with other thyroid-related symptoms, prompt medical evaluation and thyroid testing are recommended.

47. Slow Growth in Children

47. Slow Growth in Children
A young child stands beside a colorful growth chart as a pediatrician records their height during a health checkup. | Generated by Google Gemini

Thyroid hormones are essential for normal growth and development in children. They regulate bone growth, brain maturation, and overall physical development. When thyroid function is impaired—most commonly due to hypothyroidism—children may experience slowed growth rates, delayed puberty, and even developmental delays if left untreated. Growth charts may show a child dropping percentiles for height and weight compared to their peers, despite adequate nutrition and a healthy environment.

For example, a child who was previously growing along the 50th percentile for height might gradually fall to the 10th percentile over several years, and parents may notice that clothes and shoes are lasting much longer than expected. Unlike minor, temporary slowdowns in growth due to illness or stress, thyroid-related growth delays are progressive and persistent. According to the Hormone Health Network, pediatricians recommend thyroid screening for any child with unexplained short stature, slow growth velocity, or delayed puberty.

If your child is not growing as expected or shows other symptoms such as fatigue, constipation, or dry skin, prompt evaluation—including thyroid function testing—can lead to early diagnosis and treatment, supporting normal growth and development.

48. Delayed Puberty

48. Delayed Puberty
A concerned teen sits with a doctor, discussing growth and development challenges related to delayed puberty and health. | Generated by Google Gemini

Hypothyroidism can significantly delay the onset of puberty in children and adolescents. Thyroid hormones are vital for the regulation of reproductive hormones and the maturation of the hypothalamic-pituitary-gonadal axis, which orchestrates puberty. When thyroid function is low, the normal rise in sex hormones—such as estrogen in girls and testosterone in boys—is disrupted, resulting in delayed development of secondary sexual characteristics like breast growth, pubic hair, voice changes, and menstrual periods.

Normal variations in puberty timing are common, with most children beginning puberty between ages 8 and 13 for girls and 9 and 14 for boys. Some may naturally develop earlier or later than peers without underlying health problems. However, when puberty is significantly delayed—such as a girl who has not started breast development by age 13 or a boy with no testicular enlargement by age 14—an underlying cause such as hypothyroidism should be considered. According to the Endocrine Society, any child with delayed or stalled puberty should be evaluated by a pediatrician or pediatric endocrinologist.

If you notice signs of delayed puberty in your child, especially alongside other symptoms like fatigue, slow growth, or weight gain, consult a healthcare provider to discuss thyroid function testing and further evaluation.

49. Hoarse Cry in Infants

49. Hoarse Cry in Infants
A tiny infant with flushed cheeks lets out a hoarse cry, tears welling in bright, searching eyes. | Generated by Google Gemini

Congenital hypothyroidism, a condition present at birth, can manifest as a hoarse or raspy cry in infants. This occurs because low thyroid hormone levels lead to the accumulation of mucopolysaccharides in the tissues, including the vocal cords and larynx, causing swelling and thickening. As a result, an affected infant’s cry may sound deeper, rougher, or more strained than the soft, high-pitched cry typical of healthy newborns. This symptom is often accompanied by other subtle signs like poor feeding, constipation, prolonged jaundice, or a puffy face.

Most newborns experience variations in their cry due to hunger, discomfort, or illness, but these are usually temporary and resolve with care or time. A persistently hoarse or abnormal cry, especially if it is present from birth or develops within the first weeks of life, may point to an underlying thyroid disorder. According to the National Center for Biotechnology Information (NCBI), early detection and treatment of congenital hypothyroidism are crucial for preventing developmental delays and supporting normal growth.

If you notice your infant has a consistently hoarse cry, consult your pediatrician immediately for evaluation and thyroid screening to ensure timely diagnosis and intervention.

50. Family History of Thyroid Disease

50. Family History of Thyroid Disease
A smiling family of three sits together on a couch, discussing their shared genetics and family health history. | Generated by Google Gemini

Genetics play a significant role in the risk of developing thyroid disorders. Conditions such as Hashimoto’s thyroiditis, Graves’ disease, and other autoimmune thyroid diseases tend to run in families, indicating a hereditary predisposition. If one or more close relatives—such as parents, siblings, or grandparents—have been diagnosed with thyroid problems, the likelihood that others in the family may develop similar issues increases. This genetic connection is particularly strong for autoimmune thyroid diseases, but can also influence the risk for thyroid nodules and, more rarely, thyroid cancer.

For example, a woman may discover that both her mother and aunt have hypothyroidism, and later develop symptoms herself in adulthood. Recognizing this pattern can lead to earlier consideration of thyroid dysfunction, even before symptoms become severe. According to the American Thyroid Association, individuals with a family history of thyroid disease should be proactive about regular thyroid screening and should discuss their risk with their healthcare provider.

Early detection through screening in at-risk individuals can facilitate prompt diagnosis, prevent complications, and help manage thyroid health more effectively throughout life. If you have a family history of thyroid disease, consider discussing preventive screening with your physician.

Conclusion

Conclusion
Early recognition of thyroid disorder symptoms enables timely intervention and supports lifelong health.

Recognizing the diverse and sometimes subtle clues of thyroid disorders is vital for protecting long-term health. Symptoms such as persistent fatigue, unexplained weight changes, mood disturbances, and physical changes should not be ignored, as early detection can prevent serious complications. Timely action, including discussing concerns with a healthcare provider and pursuing appropriate screening, is key to effective management and improved quality of life. If you notice any persistent or unexplained symptoms, consult your provider and consider thyroid testing. For more information, visit the American Thyroid Association or speak with your healthcare team about your individual risk and options for early detection.

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