Health

Help! Why Is My Hair Falling Out in Clumps?

42. Over-Brushing or Aggressive Hair Handling Over-brushing or handling hair aggressively—such as forcefully towel drying, detangling, or styling—can cause significant mechanical damage that leads to breakage… Alina Yasinskaya - August 28, 2025

Hair loss affects over 80 million people in the US and nearly 8 million in the UK, according to data from the American Academy of Dermatology and NHS. As a vital part of the integumentary system, healthy hair signals overall well-being. Unfortunately, many people detect abnormal hair shedding only after significant loss occurs, making timely intervention difficult. Understanding the underlying causes and recognizing early warning signs are essential in addressing the emotional and physical challenges posed by sudden, excessive hair fall.

1. Telogen Effluvium

1. Telogen Effluvium
A worried woman examines strands of hair in her hand, illustrating stress-induced telogen effluvium and noticeable hair shedding. | Generated by Google Gemini

Telogen effluvium is a common cause of sudden hair shedding, occurring when a significant number of hair follicles prematurely shift from the growth (anagen) phase into the resting (telogen) phase. This process is often triggered by physical or emotional stressors such as major illness, high fever, childbirth, or surgery. For example, it is not unusual for individuals to notice increased hair shedding one to three months following a surgical procedure, as the body responds to the trauma by reallocating energy to vital organs rather than hair growth.

Typically, people experiencing telogen effluvium will observe large clumps of hair coming out during washing or brushing, without visible bald patches. The scalp may appear thinner overall, but not patchy. Key clues include a sudden onset of shedding that lasts several weeks to months and a clear association with a stressful event. Fortunately, telogen effluvium is usually temporary and resolves as the body recovers. For more details, visit the American Academy of Dermatology’s guide to telogen effluvium.

2. Alopecia Areata

2. Alopecia Areata
A close-up view of a scalp showing patchy hair loss, a common sign of autoimmune-related alopecia areata. | Generated by Google Gemini

Alopecia areata is an autoimmune disorder in which the body’s immune system mistakenly targets hair follicles, leading to hair loss in round, patchy clumps. Unlike diffuse shedding, alopecia areata typically presents as smooth, bald spots, often about the size of a coin, appearing suddenly on the scalp or other hair-bearing areas. The surrounding skin remains healthy, and regrowth may occur, but the cycle of loss and regrowth can be unpredictable. A well-known example is actress Jada Pinkett Smith, who has spoken publicly about her experience with this condition.

If you notice one or more round bald patches or rapid clump loss with sharply defined borders, it’s important to consult a dermatologist promptly. Early medical intervention can help manage symptoms and sometimes encourage hair regrowth. Signs that warrant professional advice include rapid progression of bald spots, loss of eyebrow or eyelash hair, or any discomfort or redness in the affected areas. For more information about alopecia areata, visit the NHS overview on alopecia areata or the National Alopecia Areata Foundation.

3. Androgenetic Alopecia

3. Androgenetic Alopecia
A man in his thirties reveals thinning hair at the crown, a common sign of androgenetic pattern baldness. | Generated by Google Gemini

Androgenetic alopecia, commonly known as male or female pattern baldness, is the most prevalent form of hair loss worldwide and is driven primarily by genetics and hormonal changes. In men, this condition often begins with a receding hairline and thinning at the crown, eventually leading to partial or complete baldness. In contrast, women typically experience diffuse thinning across the top of the scalp while maintaining their frontal hairline, resulting in a widening part rather than distinct bald patches.

Early warning signs for both genders include gradual thinning of hair, increased shedding during brushing or showering, and a noticeable decrease in overall hair volume. Unlike other forms of hair loss, androgenetic alopecia progresses slowly over years. Family history is a significant risk factor, and recognizing these early signs can help individuals seek timely medical advice and explore treatment options. For further information and illustrations comparing male and female patterns, visit the NHS guide on hair loss or review resources from the American Academy of Dermatology on pattern baldness.

4. Traction Alopecia

4. Traction Alopecia
A woman examines thinning patches along her hairline, highlighting the effects of tight hairstyles and traction alopecia. | Generated by Google Gemini

Traction alopecia arises when hair is subjected to sustained tension or pulling, frequently due to certain hairstyles. Tight ponytails, braids, cornrows, buns, hair extensions, and dreadlocks can all place excessive mechanical stress on hair follicles, eventually leading to localized hair loss. This condition is especially common among individuals who wear such styles for cultural, aesthetic, or occupational reasons. For instance, ballet dancers who secure their hair tightly for performances and individuals in professions requiring neat, pulled-back hair may be at increased risk. Certain cultural practices, such as traditional African and Caribbean braiding techniques, are also associated with traction alopecia.

Early signs include redness, bumps, and a receding hairline—most often around the temples, forehead, or nape of the neck. Over time, the affected areas can develop thinning or bald patches. Prevention involves regularly alternating hairstyles, avoiding excessive tension, and allowing hair to rest between styles. Using softer hair accessories and being mindful of scalp discomfort are practical steps to minimize risk. For more information and prevention tips, visit the American Academy of Dermatology’s traction alopecia resource or review advice from the NHS.

5. Trichotillomania

5. Trichotillomania
A young woman sits thoughtfully, gently pulling at strands of her hair, illustrating the struggle with trichotillomania. | Generated by Google Gemini

Trichotillomania is an impulse control disorder characterized by a persistent urge to pull out one’s own hair, leading to noticeable hair loss and psychological distress. This condition often affects the scalp, eyebrows, and eyelashes, and can result in patchy bald spots or thinning areas. While the exact causes remain unclear, psychological triggers such as stress, anxiety, boredom, or tension frequently precede hair-pulling episodes. The act of pulling may offer temporary relief or satisfaction but is typically followed by feelings of shame or guilt.

Trichotillomania can begin in childhood or adolescence and may persist into adulthood if left untreated. Individuals may attempt to hide their behavior, making it challenging for loved ones to recognize the disorder. If you notice recurrent hair loss in irregular patterns, accompanied by signs of emotional distress or repeated attempts to stop the behavior, it may be time to seek professional help. Behavioral therapy, particularly cognitive behavioral therapy (CBT), is considered an effective treatment for managing the condition and reducing hair-pulling urges. For more information and support, visit the NHS guide to trichotillomania or the Trichotillomania Learning Center.

6. Chemotherapy-Induced Hair Loss

6. Chemotherapy-Induced Hair Loss
A brave cancer patient sits in a hospital chair during chemotherapy, gently touching her newly bald head. | Generated by Google Gemini

Chemotherapy-induced hair loss occurs because many cancer treatments target rapidly dividing cells, a category that includes both cancer cells and hair follicle cells. As a result, individuals undergoing chemotherapy often experience sudden, widespread hair shedding, sometimes losing hair in large clumps not just on the scalp, but also from eyebrows, eyelashes, and body hair. This type of hair loss can be distressing, as it is a visible reminder of illness and treatment.

Many patients describe feeling a loss of identity or confidence, but also report finding community and solidarity among others facing similar challenges. Practical coping strategies include using soft head coverings, wigs, scarves, or hats, and taking gentle care of the scalp to minimize irritation. Some people use cooling caps during chemotherapy to reduce hair loss, though effectiveness varies. Emotional support from friends, family, and counseling services can make a meaningful difference during this time. For further insight, including real patient experiences and advice, visit American Cancer Society’s guide to hair loss and cancer treatment and the Macmillan Cancer Support hair loss resource.

7. Radiation Therapy

7. Radiation Therapy
A close-up view of a person’s scalp reveals a smooth, hairless patch caused by recent radiation therapy treatment. | Generated by Google Gemini

Radiation therapy can cause localized hair loss when beams are directed at the scalp or head, damaging the hair follicles within the targeted area. Unlike chemotherapy, which typically results in diffuse hair shedding across the entire scalp and body, radiation-induced hair loss is limited to the specific site of treatment. The extent and permanence of hair loss depend on the dose and duration of radiation; in some cases, regrowth may be patchy or incomplete.

Patients may notice hair falling out in clumps within weeks of starting radiation, often accompanied by scalp tenderness, redness, or dryness. Scalp care during and after radiation is crucial to minimize discomfort and promote recovery. Recommended options include using gentle, fragrance-free shampoos, avoiding harsh hair treatments, protecting the scalp from sun exposure with hats or scarves, and applying moisturizers to soothe irritation. For more details on managing hair loss and scalp health during radiation, consult the American Cancer Society’s radiation therapy overview and the Macmillan Cancer Support’s guide to radiation-related hair loss.

8. Iron Deficiency Anemia

8. Iron Deficiency Anemia
A close-up view of a pale scalp, highlighting a common physical sign associated with iron deficiency anemia. | Generated by Google Gemini

Iron deficiency anemia is a significant contributor to hair loss, particularly in women of childbearing age. Iron is essential for healthy hair follicle metabolism and growth, as it helps carry oxygen to the cells, including those that drive hair production. When iron levels are low, hair follicles may enter the resting (telogen) phase prematurely, resulting in increased shedding and noticeable thinning. This type of hair loss often occurs gradually and can be mistaken for other conditions, but is reversible with appropriate treatment.

Compared to other nutritional deficiencies—such as low zinc or vitamin D, which can also impact hair health—iron deficiency is among the most common worldwide. Symptoms may include fatigue, weakness, pale skin, and brittle nails, alongside hair loss. If you suspect iron deficiency, especially if you follow a vegetarian or vegan diet, have heavy menstrual periods, or experience unexplained hair loss, talk to your healthcare provider about screening for anemia with a simple blood test. For more information on symptoms and treatment, visit the NHS guide to iron deficiency anemia or CDC’s resource on iron deficiency anemia.

9. Thyroid Disorders

9. Thyroid Disorders
A woman examines strands of hair in her brush, symbolizing hair loss linked to thyroid gland hormonal imbalance. | Generated by Google Gemini

Thyroid disorders, including hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid), have a profound effect on the hair growth cycle. Both conditions disrupt the normal production of thyroid hormones, which play a crucial role in regulating metabolism and hair follicle health. When hormone levels are imbalanced, hair may shift prematurely into the resting (telogen) phase, leading to diffuse thinning and increased shedding across the scalp.

A common scenario involves a patient experiencing persistent fatigue, unexplained weight changes, and thinning hair. For example, Jane, a 34-year-old teacher, noticed her ponytail was thinner and felt constantly tired. Blood tests confirmed she had hypothyroidism. With proper treatment, including thyroid hormone replacement, Jane’s hair gradually recovered and her energy levels improved. Recognizing additional symptoms like dry skin, sensitivity to cold, or heart palpitations can be important clues.

If you observe hair loss accompanied by changes in mood, energy, or metabolism, consult a healthcare professional to check your thyroid function. Early diagnosis and management are key to restoring both health and hair. For more details, review the NHS guide to hypothyroidism symptoms and American Thyroid Association’s resource on hyperthyroidism.

10. Polycystic Ovary Syndrome (PCOS)

10. Polycystic Ovary Syndrome (PCOS)
A woman gently parts her hair to reveal thinning along the scalp, highlighting hormonal hair loss from PCOS. | Generated by Google Gemini

Polycystic Ovary Syndrome (PCOS) is a common endocrine disorder affecting women of reproductive age, characterized by imbalanced levels of androgens (male hormones). These hormonal shifts can disrupt the natural hair growth cycle, often resulting in hair thinning on the scalp and increased shedding, sometimes in noticeable clumps. While excess facial or body hair growth (hirsutism) is also a hallmark of PCOS, scalp hair loss can be a particularly distressing symptom for many women.

PCOS-related hair loss differs from other endocrine issues, such as thyroid disorders, by typically presenting with a combination of symptoms including irregular menstrual cycles, acne, and weight gain. The pattern of hair thinning in PCOS often resembles female pattern baldness, with diffuse thinning at the crown and a widening part. If you notice these signs—especially alongside changes in your menstrual cycle or increased body hair—it’s important to seek medical evaluation. Diagnosis usually involves a combination of physical examination, hormone blood tests, and an ultrasound of the ovaries.

For further information and screening guidance, visit the NHS overview on PCOS symptoms or the CDC’s PCOS resource.

11. Lupus

11. Lupus
A close-up view of a scalp with patchy hair loss and visible redness, highlighting lupus-related autoimmune inflammation. | Generated by Google Gemini

Lupus, formally known as systemic lupus erythematosus (SLE), is an autoimmune disorder in which the immune system attacks healthy tissues throughout the body, including the skin and hair follicles. This chronic inflammation can result in both diffuse hair thinning and patchy hair loss. Some individuals experience gradual shedding across the scalp, while others develop distinct bald patches, sometimes accompanied by scaly, red skin lesions where hair fails to regrow.

For example, one patient with lupus reported overall thinning and a “fragile” texture to her hair, while another developed small, round bald spots that left behind scars. Warning signs of lupus-related hair loss often include unexplained fatigue, joint pain, skin rashes (especially a butterfly-shaped rash across the cheeks and nose), and increased sensitivity to sunlight. Because these symptoms can overlap with other conditions, it’s important to consult a healthcare provider if you notice sudden or unexplained hair loss alongside systemic symptoms.

Early diagnosis and treatment of lupus can help minimize hair loss and other complications. For more information on lupus and its effects on hair, visit the Lupus Foundation of America and the NHS guide to lupus.

12. Scalp Psoriasis

12. Scalp Psoriasis
Thick, silvery scales cover the scalp, with clumps of hair visible among patches of irritated, flaky skin. | Generated by Google Gemini

Scalp psoriasis is a chronic autoimmune condition characterized by thick, scaly, and often silvery patches on the scalp. These plaques can cause significant itching, irritation, and inflammation, which frequently leads to hair breakage and shedding in clumps. Unlike simple dandruff, which presents as loose white flakes without underlying skin plaques, scalp psoriasis causes more pronounced redness, scaling, and sometimes even bleeding when scales are picked or scratched away.

Hair loss associated with scalp psoriasis is usually due to the trauma from scratching, excessive picking, or the physical removal of scales, rather than the disease directly attacking the follicles. Unlike dandruff, which typically resolves with over-the-counter shampoos, psoriasis often persists and can become more severe without prescription treatments. Signs that warrant a dermatological evaluation include persistent thick patches, significant discomfort, or hair falling out in clumps despite regular dandruff treatment.

Early diagnosis and proper management can prevent further scalp damage and excessive hair loss. For more information on symptoms and when to seek help, visit the National Psoriasis Foundation’s scalp psoriasis guide or the NHS resource on psoriasis.

13. Seborrheic Dermatitis

13. Seborrheic Dermatitis
Close-up view of a scalp with visible flaking and redness, showing the oily appearance typical of seborrheic dermatitis. | Generated by Google Gemini

Seborrheic dermatitis is a common inflammatory condition that affects the scalp, resulting in redness, excess oil (sebum), and flaky, yellowish scales. This chronic irritation can cause temporary hair loss, often manifesting as clumps of hair coming out when scratching or washing the scalp. The inflammation and overproduction of oil disrupt the normal hair growth environment, leading to increased shedding and a sensation of scalp discomfort or itchiness.

Distinguishing seborrheic dermatitis from fungal infections such as tinea capitis (scalp ringworm) is important for proper treatment. While both conditions can cause flaking and hair loss, fungal infections often produce well-defined, circular bald patches and may include broken hairs or black dots at the scalp surface. Seborrheic dermatitis, on the other hand, usually presents as more diffuse scaling and greasy patches without sharp borders. Antifungal shampoos and topical steroids are commonly used to manage seborrheic dermatitis, while true fungal infections require oral antifungal medications.

If you notice persistent oily flakes, scalp redness, or temporary hair thinning, consult a dermatologist for accurate diagnosis and care. For more information, visit the American Academy of Dermatology’s seborrheic dermatitis resource and the NHS guide on seborrheic dermatitis.

14. Fungal Scalp Infections (Tinea Capitis)

14. Fungal Scalp Infections (Tinea Capitis)
A close-up view of a child’s scalp reveals patchy hair breakage and flaking caused by tinea capitis, a common scalp fungus. | Generated by Google Gemini

Fungal scalp infections, particularly tinea capitis (commonly known as ringworm of the scalp), are caused by dermatophyte fungi invading the hair shafts and follicles. This infection leads to inflammation, breakage of hairs near the scalp surface, and the formation of round, scaly bald patches. Affected areas may appear red, swollen, or dotted with black spots where hair has broken off. Tinea capitis is highly contagious and most often affects children, especially in group settings such as schools or daycare centers.

In a typical school outbreak, several children might develop itchy, patchy hair loss within a short period, sometimes accompanied by swollen lymph nodes or low-grade fever. Parents should be alert to signs such as persistent scalp itchiness, scaling, or small bald spots with broken hairs. Early intervention is crucial to prevent the spread to others and to minimize permanent hair loss or scarring. Oral antifungal medications are usually required for effective treatment, as topical solutions alone are insufficient.

For more details on symptoms, prevention, and treatment, visit the CDC’s guide to ringworm and the NHS information on ringworm.

15. Lichen Planopilaris

15. Lichen Planopilaris
Patches of red, inflamed scalp with visible hair loss highlight the scarring alopecia caused by lichen planopilaris. | Generated by Google Gemini

Lichen planopilaris (LPP) is a rare, chronic inflammatory condition that targets and destroys hair follicles, leading to irreversible scarring and permanent hair loss. This disease is a form of primary scarring alopecia (cicatricial alopecia) and typically presents as patches of hair loss with associated redness, scaling, and sometimes tenderness or itching. Over time, the affected skin may appear shiny or smooth due to the loss of follicles and scarring beneath the surface.

LPP differs from other scarring alopecias, such as central centrifugal cicatricial alopecia (CCCA), by its pattern and symptoms. While CCCA often starts at the crown and spreads outward, LPP can occur anywhere on the scalp and is usually accompanied by visible signs of inflammation at the hairline or patch edges. Early recognition and intervention are critical because once follicles are scarred, regrowth is not possible. Dermatologists may recommend potent topical or oral anti-inflammatory medications to halt disease progression.

If you notice patches of hair loss with scalp redness, scaling, or discomfort, it’s vital to seek prompt medical evaluation. For more on lichen planopilaris and other scarring alopecias, visit the American Academy of Dermatology’s guide to scarring alopecia and the NHS resource on lichen planus.

16. Nutritional Deficiencies (Zinc, Biotin, Protein)

16. Nutritional Deficiencies (Zinc, Biotin, Protein)
A handful of fallen hair strands rests beside a bottle of biotin supplements, highlighting concerns about nutritional deficiency. | Generated by Google Gemini

Poor intake of essential nutrients such as zinc, biotin, and protein can directly affect hair health, often resulting in weak, brittle strands and increased shedding. Zinc plays a crucial role in cell repair and growth, biotin supports keratin production, and adequate protein intake provides the building blocks for hair structure. Deficiencies in any of these nutrients may cause hair to fall out in clumps or appear noticeably thin and fragile.

Stories of dietary improvement often highlight the importance of a balanced, nutrient-rich diet. For example, individuals recovering from restrictive diets or eating disorders frequently report significant hair regrowth and strength after incorporating more lean meats, eggs, legumes, nuts, and whole grains. Vegetarians and vegans, as well as those with gastrointestinal conditions affecting absorption, may be at increased risk for deficiencies and should pay careful attention to their nutrient intake.

If you notice persistent hair loss alongside brittle nails, skin changes, or unexplained fatigue, it may be time to consult a registered dietitian for assessment and personalized recommendations. Blood tests can help identify specific deficiencies. For more on the role of nutrition in hair health, visit the Harvard T.H. Chan School of Public Health’s guide to B vitamins and the NIH fact sheet on zinc.

17. Crash Diets & Rapid Weight Loss

17. Crash Diets & Rapid Weight Loss
A young woman stares worriedly at clumps of hair in her brush, a result of rapid crash dieting. | Generated by Google Gemini

Crash diets and rapid weight loss can have a dramatic impact on hair health. When the body experiences sudden calorie restriction, it prioritizes vital functions over hair growth, causing a significant number of follicles to enter the telogen (resting) phase. This shift often results in noticeable hair shedding, typically two to three months after the diet or weight loss event. The phenomenon, known as telogen effluvium, is especially common among those who follow fad diets lacking sufficient protein, healthy fats, or essential micronutrients.

Cases have been reported where individuals adopting extreme diets—such as juice cleanses, ketogenic plans with insufficient calories, or highly restrictive “detox” regimens—began noticing large clumps of hair falling out during brushing or showering. The reassuring news is that once normal eating habits are restored and nutritional needs are met, hair growth often resumes, though it can take six months or more for noticeable recovery.

If you’re considering significant dietary changes or have experienced unexpected hair loss after rapid weight loss, consult a healthcare professional or registered dietitian for guidance. For further reading, see the NCBI article on nutritional factors in hair loss and the Harvard T.H. Chan School of Public Health’s diet reviews.

18. Postpartum Hair Loss

18. Postpartum Hair Loss
A new mother gently examines strands of hair in her hand, navigating the challenges of postpartum hair loss. | Generated by Google Gemini

Postpartum hair loss, also known as postpartum telogen effluvium, is a common and temporary phenomenon experienced by many new mothers. During pregnancy, elevated estrogen levels prolong the growth phase of hair, leading to thicker, fuller locks. However, after childbirth, hormone levels rapidly decline, causing a large number of hair follicles to enter the resting (telogen) phase simultaneously. This hormonal shift results in noticeable shedding, often seen as clumps of hair in the shower or on the pillow, typically peaking around three to four months postpartum.

This pattern differs from the lush hair growth seen during pregnancy, and while the shedding can be alarming, it is a normal physiological response that usually resolves within six to twelve months. To support hair recovery, postpartum women are encouraged to maintain a balanced diet, avoid tight hairstyles, use gentle hair care products, and manage stress. If excessive shedding persists beyond a year or is accompanied by other symptoms like fatigue or brittle nails, consulting a healthcare provider is recommended to rule out anemia or thyroid issues.

For more information and tips for managing postpartum hair loss, visit the American Academy of Dermatology’s postpartum hair loss resource and the NHS guide to hair loss after pregnancy.

19. Menopause

19. Menopause
A graceful older woman gently touches her thinning hair, reflecting on her journey through menopause with quiet strength. | Generated by Google Gemini

Menopause marks a significant hormonal transition in a woman’s life, with estrogen levels declining sharply. Estrogen plays a key role in maintaining hair density and supporting the growth phase of hair follicles. As these hormone levels drop, many women notice their hair becoming thinner, more brittle, and falling out in greater quantities, sometimes in clumps. This process, known as menopausal or female pattern hair loss, typically manifests as a gradual widening of the part and diffuse thinning across the scalp.

Consider the case of Linda, age 54, who began experiencing increased hair shedding and a visible reduction in her ponytail’s thickness during her perimenopausal years. After consulting her healthcare provider, she learned that these changes were linked to menopause and received guidance on managing stress, optimizing nutrition, and choosing gentle hair products. Linda also learned to avoid harsh chemical treatments and excessive heat styling, which can exacerbate hair fragility during this time.

For midlife women, practical advice includes eating a balanced diet rich in iron, vitamin D, and protein, considering stress-reduction strategies, and consulting a healthcare provider about hormone therapy or topical treatments if hair loss is severe. For more on menopause and hair changes, visit the NHS menopause symptoms guide and Harvard Health’s overview on menopause and hair loss.

20. Birth Control Pills & Hormonal Medications

20. Birth Control Pills & Hormonal Medications
A young woman examines a pack of birth control pills, concerned about noticeable hair thinning near her hairline. | Generated by Google Gemini

Hormonal contraceptives, including birth control pills, patches, and injections, can influence the hair growth cycle in sensitive individuals. These medications alter the body’s hormone levels, which may trigger telogen effluvium—temporary hair shedding—especially when starting, stopping, or switching contraceptives. Some women experience increased hair loss when taking pills with higher androgenic activity, while others notice shedding after discontinuing a hormone-based medication, as the body adjusts to shifting hormone levels.

Other hormonal medications, such as hormone replacement therapy (HRT) or drugs for polycystic ovary syndrome (PCOS), can also impact hair density and shedding patterns. For example, a woman may begin taking a new birth control pill and notice increased hair fall within a few months, or a person treated for endometriosis may experience thinning as a side effect of medication. These effects are usually reversible, but persistent or severe hair loss warrants medical attention.

If you suspect hormonal medications are contributing to hair shedding, consult your healthcare provider. They may recommend alternative formulations, dose adjustments, or additional testing to rule out underlying causes. For more detailed information, visit the American Academy of Dermatology’s resource on birth control and hair loss and the NHS guide to birth control side effects.

21. Chronic Illness (e.g., Diabetes, Kidney Disease)

21. Chronic Illness (e.g., Diabetes, Kidney Disease)
A confident woman with visible hair loss checks her blood sugar, highlighting strength and resilience in managing diabetes. | Generated by Google Gemini

Chronic illnesses such as diabetes and kidney disease can have a profound effect on hair health due to disruptions in metabolic and vascular pathways. These conditions often impair blood flow, nutrient delivery, and waste removal at the cellular level, creating an environment where hair follicles struggle to thrive. For example, poorly managed diabetes can lead to microvascular complications that reduce scalp circulation, while kidney disease may cause imbalances in essential nutrients and hormones, both resulting in increased hair shedding or thinning.

Real-world cases include individuals with long-standing diabetes who notice gradual thinning or patchy hair loss, sometimes accompanied by delayed wound healing or changes in skin texture. Patients with end-stage renal disease may report hair becoming dull, brittle, and falling out in clumps, especially during periods of metabolic instability or after dialysis. These symptoms are often overlooked, but they can signal suboptimal disease control or underlying nutritional deficiencies.

If you live with a chronic illness and experience sudden or persistent hair loss, discuss this with your physician, as it may indicate the need for adjustments in treatment, dietary support, or further investigation. For more information, see the American Diabetes Association’s guide to skin and hair complications and the National Kidney Foundation’s page on hair health.

22. Medications (Anticoagulants, Beta Blockers, etc.)

22. Medications (Anticoagulants, Beta Blockers, etc.)
A cluster of pill bottles sits beside a hairbrush filled with loose strands, hinting at medication side effects. | Generated by Google Gemini

Numerous medications are associated with hair loss as a potential side effect. Common culprits include anticoagulants (such as warfarin and heparin), beta blockers (used for high blood pressure and heart conditions), antidepressants, anticonvulsants, retinoids (vitamin A derivatives), and certain cholesterol-lowering drugs. These medications can disrupt the hair growth cycle, often triggering telogen effluvium by pushing more follicles into the shedding phase prematurely. Some drugs may also alter nutrient absorption or blood supply to the scalp, further impacting hair health.

For example, a patient prescribed a beta blocker for hypertension noticed increased hair shedding about three months after starting treatment. Upon consultation, her physician recognized the medication as a likely contributor and discussed alternative therapies. In many cases, medication-induced hair loss is reversible once the offending drug is discontinued or replaced, but decisions should always be made in partnership with a healthcare provider.

If you observe new or unexplained hair loss after starting a medication, do not stop taking the drug on your own. Instead, consult your doctor or pharmacist to review your treatment plan and explore safer options. For comprehensive lists and more information, visit the American Academy of Dermatology’s page on medications and hair loss and the NHS medicines guide.

23. Major Surgery or Hospitalization

23. Major Surgery or Hospitalization
A post-surgical patient rests in a hospital bed, surrounded by monitoring equipment and caring healthcare professionals. | Generated by Google Gemini

The physical and emotional stress associated with major surgery or hospitalization can significantly impact the hair growth cycle, often triggering telogen effluvium. During these periods of bodily trauma, the body redirects its resources toward healing vital organs, causing many hair follicles to prematurely enter the resting (telogen) phase. This shift typically results in noticeable hair shedding, often in clumps, two to three months following the stressful event.

Both elective procedures, such as joint replacements or cosmetic surgeries, and emergency hospitalizations for acute illness or injury can provoke this response. Patients recovering from planned surgeries may expect this temporary hair loss as part of the healing process, while those hospitalized unexpectedly might find the shedding more alarming due to its abrupt onset. Fortunately, in most cases, hair growth resumes within six to twelve months once the underlying stress has resolved and the body regains its equilibrium.

Patients should focus on a balanced diet, gentle hair care, and stress management during recovery. If shedding persists beyond a year or is accompanied by other symptoms, consult a healthcare provider to rule out additional causes. For further reading, visit the American Academy of Dermatology’s telogen effluvium guide and the NHS resource on hair loss.

24. Severe Emotional Stress

24. Severe Emotional Stress
A distressed woman sits with tears streaming down her face, clutching a handful of her own hair in frustration. | Generated by Google Gemini

Severe emotional stress is a powerful trigger for sudden hair loss, often causing a condition known as telogen effluvium. Psychological distress—such as the death of a loved one, divorce, job loss, or significant life changes—can shock the body and disrupt the hair growth cycle. During these periods, an increased number of hair follicles shift prematurely into the resting (telogen) phase, leading to noticeable shedding, sometimes in large clumps, several weeks or months after the stressful event.

People frequently report finding more hair in their brush or shower drain after experiencing events like moving, breakup, or prolonged anxiety. While this shedding can be distressing, it is typically temporary. Effective stress management is crucial for recovery and may include mindfulness exercises, regular physical activity, talking to supportive friends or professionals, and maintaining a healthy lifestyle.

If hair loss persists beyond six months or is accompanied by other symptoms such as sleep disruption, appetite changes, or mood swings, consider consulting a healthcare provider or mental health professional. For more on the link between stress and hair loss, visit the American Academy of Dermatology’s resource on stress and hair loss and the NHS guide to managing stress.

25. COVID-19 and Other Infections

25. COVID-19 and Other Infections
A young woman examines strands of hair in her hand, concerned about increased shedding after recovering from COVID-19 infection. | Generated by Google Gemini

Since the onset of the COVID-19 pandemic, dermatologists have observed a significant rise in cases of hair shedding, often occurring several weeks after recovery from the virus. This phenomenon is usually a form of telogen effluvium, triggered by the physical stress of infection, inflammation, and high fever. Research shows that COVID-19, like other viral illnesses such as influenza or severe respiratory infections, can disrupt the normal hair growth cycle, pushing more follicles into the shedding phase. Patients often report losing hair in clumps during brushing or washing, sometimes for months after their initial illness.

Recent studies, including those published in JAMA Dermatology and summarized by the American Academy of Dermatology, confirm this link and suggest that most cases resolve within six to nine months. If hair loss persists beyond this window, is accompanied by scalp discomfort, or is associated with other unusual symptoms, a medical evaluation is recommended to rule out additional causes or complications. Ongoing support, proper nutrition, and stress management can aid in recovery during this period.

26. Poor Scalp Hygiene

26. Poor Scalp Hygiene
A person gently massages shampoo into their scalp, creating a rich lather that highlights the importance of hair care. | Generated by Google Gemini

Poor scalp hygiene can be an overlooked contributor to hair loss and shedding in clumps. Infrequent washing allows sebum, dead skin cells, and environmental pollutants to accumulate on the scalp, creating an unhealthy environment for hair follicles. This buildup can clog follicles, promote inflammation, and even foster the growth of bacteria or fungi, all of which may weaken hair and lead to increased shedding. Conversely, using harsh shampoos, excessive heat, or over-washing can strip the scalp of its natural oils, causing irritation, dryness, and breakage.

Different scalp care routines can have significant effects on hair health. Some people benefit from washing their hair every other day with mild, sulfate-free shampoos, while others with drier scalps may wash less frequently and use nourishing treatments. Overuse of styling products or infrequent cleansing can make the scalp feel greasy and itchy, whereas a balanced routine helps maintain a clean and comfortable scalp. If you notice persistent buildup, itching, or hair falling out in clumps, it’s wise to reassess your hair care habits.

For scalp care recommendations and guidance, visit the American Academy of Dermatology’s scalp care tips and the NHS hair care tips.

27. Allergic Reactions to Hair Products

27. Allergic Reactions to Hair Products
A woman sits uncomfortably, scratching her scalp with visible redness after experiencing an allergic reaction to hair dye. | Generated by Google Gemini

Allergic reactions to ingredients in hair products—such as dyes, shampoos, conditioners, or styling agents—can lead to scalp inflammation and hair loss in clumps. Common allergens include paraphenylenediamine (PPD) in hair dyes, fragrances, preservatives, and certain sulfates or parabens. When the scalp reacts to these substances, symptoms may include redness, itching, swelling, or blistering. Persistent inflammation can weaken hair follicles and trigger increased shedding or even patchy hair loss.

To minimize the risk of an allergic reaction, always perform a patch test before applying new products to your scalp or hair. Apply a small amount of the product behind your ear or on your inner arm and wait 24-48 hours for any signs of irritation. If redness, swelling, or discomfort occurs, avoid using the product. Opt for fragrance-free, hypoallergenic, or dermatologist-recommended formulas when possible, especially if you have sensitive skin or a history of allergies.

If you experience unexplained scalp irritation or sudden hair loss after using a new product, discontinue use immediately and consult a healthcare professional or dermatologist. For more information, explore the American Academy of Dermatology’s advice on choosing hair products and the NHS resource on allergies.

28. Overprocessing (Bleaching, Perms, Relaxers)

28. Overprocessing (Bleaching, Perms, Relaxers)
Strands of hair show visible breakage and dryness after a harsh bleaching and chemical treatment process. | Generated by Google Gemini

Chemical treatments such as bleaching, perms, and relaxers can significantly weaken the hair shaft, making hair more susceptible to breakage and shedding in clumps. These processes alter the hair’s natural structure by breaking down proteins or disrupting bonds to change color, shape, or texture. Frequent or improper application can strip hair of moisture, cause split ends, and lead to visible thinning, especially when multiple treatments are layered or performed too often.

In-salon treatments tend to be safer, as professionals assess hair health and apply products with appropriate timing and technique. However, even under expert care, repeated chemical processing increases risk. At-home treatments, especially those done without proper instructions or patch testing, can lead to severe damage. Users often report hair breaking off in the shower, excessive shedding during brushing, or even patches of brittle, lifeless hair after a DIY coloring or straightening mishap.

Recovery involves halting chemical treatments, using deep-conditioning masks, trimming damaged ends, and choosing gentle, sulfate-free shampoos. Allowing hair to air-dry and minimizing heat styling are also beneficial. For more on safe chemical processing and recovery tips, visit the American Academy of Dermatology’s guide to repairing damaged hair and the NHS hair care tips.

29. Excessive Heat Styling

29. Excessive Heat Styling
A sleek hair dryer and a modern flat iron sit side by side, ready for effortless heat styling. | Generated by Google Gemini

Frequent use of hot tools such as hair dryers, curling irons, and straighteners can cause significant damage to the hair shaft, resulting in breakage, split ends, and hair falling out in clumps. High temperatures strip the hair of its natural moisture and weaken the protein structure, making strands more brittle and prone to snapping during brushing or styling. Over time, this cumulative damage can lead to visibly thinner hair and increased shedding, especially when combined with chemical treatments or aggressive brushing.

Safe styling practices include using heat tools on the lowest effective setting, applying a heat protectant spray, and limiting the frequency of heat styling sessions. Allowing hair to air-dry, or using microfiber towels to gently remove excess water, helps maintain hair strength. Risky habits to avoid include daily heat styling, skipping heat protection products, and using tools on soaking wet hair. Regularly trimming split ends and deep conditioning can also support healthier hair and reduce breakage.

For more advice on protecting hair from heat damage, visit the American Academy of Dermatology’s damaged hair guide and review the NHS hair care tips for daily maintenance and prevention.

30. Hard Water and Environmental Factors

30. Hard Water and Environmental Factors
A woman examines her dry, tangled hair in the mirror, signs of damage from hard water and pollution. | Generated by Google Gemini

Hard water, rich in minerals such as calcium and magnesium, can negatively impact hair health by leaving residue on the scalp and hair shafts. This buildup can make hair feel dry, dull, and more prone to breakage, leading to shedding and clumps falling out during brushing or washing. Environmental pollutants—such as smog, chlorine in swimming pools, and airborne chemicals—can also weaken hair, strip away natural oils, and aggravate scalp irritation.

Case examples illustrate these effects across different regions: Residents in areas with hard water, such as parts of the UK or the American Midwest, often report increased tangling, rough texture, and difficulty lathering shampoo. Urban dwellers exposed to high pollution levels may notice that their hair becomes lifeless or more brittle over time. Installing a showerhead water filter can help reduce mineral and chlorine exposure, while clarifying shampoos can remove buildup, though they should be used sparingly to avoid over-drying.

If you suspect environmental factors are affecting your hair, consider regular scalp cleansing, protective hairstyles, and minimizing outdoor exposure on high-pollution days. For further information, see the American Academy of Dermatology’s guide to environmental hair care and the NHS hair care tips.

31. Aging

31. Aging
A group of older adults with gray hair share laughter and stories together, highlighting the beauty of aging gracefully. | Generated by Google Gemini

Aging brings a natural and gradual reduction in both the rate of hair growth and overall hair density. As we get older, the active (anagen) phase of the hair cycle shortens, while the resting (telogen) phase becomes proportionally longer. This results in slower-growing, finer hair, and a decrease in the total number of hair follicles actively producing hair. The cumulative effect is thinning hair, increased shedding, and, in some cases, visible scalp or receding hairlines.

Comparisons across decades show that most people experience peak hair density in their 20s and 30s. By the 40s and 50s, many notice a gradual decrease in hair volume and a shift in texture—often becoming drier or more brittle. By the 60s and beyond, both men and women may observe more pronounced thinning, and men may develop balding patterns, while women notice widening parts.

It’s important to set realistic expectations for hair changes with age. While good nutrition, gentle hair care, and healthy lifestyle habits can help preserve hair quality, some degree of thinning is a normal part of the aging process. For expert advice, visit the American Academy of Dermatology’s resource on age-related hair loss and the NHS guide to hair loss.

32. Genetic Syndromes

32. Genetic Syndromes
A family examines their detailed family tree as a young child with noticeable hair loss sits in the foreground. | Generated by Google Gemini

Some rare hereditary conditions, known as genetic syndromes, can lead to early-onset or atypical patterns of hair loss. These disorders often affect not only the scalp but also other parts of the integumentary system, such as nails, teeth, and sweat glands. One well-known example is ectodermal dysplasia, a group of syndromes characterized by abnormal development of the skin, hair, nails, and teeth. Children with ectodermal dysplasia may be born with sparse, thin, or brittle hair, and may experience progressive hair loss throughout childhood or adolescence.

Other genetic conditions, such as hypotrichosis simplex or congenital alopecia, result in patchy or complete scalp hair loss at a very young age. These syndromes are usually diagnosed based on clinical features and family history, and sometimes require specialized genetic testing for confirmation. Parents noticing unusual hair patterns, delayed hair growth, or additional abnormalities in their child should consult a pediatrician or dermatologist.

Genetic counseling may be recommended for families with a history of hereditary hair disorders, especially if planning for future children or seeking clarity about prognosis. For more on genetic hair loss syndromes, visit the NIH’s resource on ectodermal dysplasias and Genetic Counselling Factsheet.

33. Hormonal Imbalances in Men

33. Hormonal Imbalances in Men
A middle-aged man with thinning hair examines a chart about testosterone levels and male hormones in a bright clinic. | Generated by Google Gemini

Hormonal imbalances, particularly involving testosterone and its potent derivative dihydrotestosterone (DHT), play a major role in male hair loss. DHT binds to androgen receptors in hair follicles, especially on the scalp, causing them to shrink (miniaturize) over time. This process leads to shorter, finer hairs and eventually to follicle dormancy, which is the hallmark of androgenetic alopecia (male pattern baldness). While mild thinning is common with age, sudden or excessive shedding may signal an underlying hormonal issue such as low testosterone, thyroid dysfunction, or even pituitary gland disorders.

Examples include young men developing rapid receding hairlines or thinning at the crown, or those experiencing hair loss alongside symptoms like fatigue, low libido, or mood changes. Such cases may warrant medical evaluation for hormonal imbalances or endocrine disorders. Hormone testing is especially appropriate if hair loss is sudden, occurs outside the typical male pattern distribution, or is accompanied by other unexplained symptoms.

Addressing the underlying hormonal cause can sometimes stabilize or improve hair loss. For more information, visit the American Academy of Dermatology’s guide to male pattern baldness and the Johns Hopkins Medicine resource on male hair loss.

34. Hormonal Imbalances in Women

34. Hormonal Imbalances in Women
A woman examines her thinning hair in the mirror, highlighting the effects of fluctuating estrogen and female hormones. | Generated by Google Gemini

Hormonal imbalances in women can dramatically affect hair growth and shedding patterns. Estrogen and progesterone typically promote hair growth and prolong the anagen (growth) phase, resulting in fuller hair. In contrast, elevated androgens—such as testosterone and dihydrotestosterone (DHT)—can trigger hair thinning, particularly at the crown or part line, mimicking male pattern baldness. Conditions like polycystic ovary syndrome (PCOS), thyroid disorders, or menopause often disrupt this delicate hormonal balance, leading to noticeable hair loss in clumps or gradual thinning.

Stories abound of women who struggled for months or years with undiagnosed hormone issues. For example, some women experience persistent hair thinning, acne, or irregular periods, only to discover PCOS after seeking medical help. Others report accelerated shedding and brittle hair during perimenopause, not realizing that declining estrogen was the culprit. In these cases, hormone testing and targeted treatments—such as oral contraceptives, anti-androgens, or thyroid medication—can help restore balance and improve hair health.

If you notice unusual hair loss alongside changes in your menstrual cycle, skin, or energy levels, consult a healthcare provider for a thorough hormonal evaluation. For more on hormone-related hair loss, see the American Academy of Dermatology’s guide to female pattern hair loss and the NHS resource on hormonal imbalance.

35. Poor Circulation

35. Poor Circulation
A close-up of hands gently massaging a scalp, stimulating blood vessels to boost circulation and promote relaxation. | Generated by Google Gemini

Poor circulation can negatively impact hair health by limiting the delivery of oxygen and essential nutrients to hair follicles, which rely on a healthy blood supply for growth and maintenance. When scalp blood flow is compromised, follicles may become weak, leading to slower growth, thinning, and increased hair shedding. Factors that reduce circulation include chronic illnesses (such as diabetes or peripheral artery disease), smoking, and a sedentary lifestyle.

Comparing sedentary and active individuals highlights the importance of circulation: those who engage in regular physical activity—such as walking, jogging, or yoga—tend to have better scalp vascularization, potentially supporting healthier hair growth. In contrast, people with limited movement or prolonged sitting often experience colder extremities, slower metabolism, and less robust hair health. Simple lifestyle modifications, such as incorporating daily exercise, scalp massages, and avoiding tight hats or hairstyles, can improve blood flow to the scalp.

If you notice persistent hair thinning and also experience symptoms like cold hands or feet, leg cramps, or delayed wound healing, consider discussing circulation and cardiovascular health with your healthcare provider. For more on the link between circulation and hair, visit the American Academy of Dermatology’s guide to scalp massage and the American Heart Association’s fitness resources.

36. Autoimmune Scalp Disorders (Other)

36. Autoimmune Scalp Disorders (Other)
Patches of hair loss are visible on the scalp, a common sign associated with certain autoimmune disorders. | Generated by Google Gemini

In addition to alopecia areata and lupus, several less common autoimmune scalp disorders can cause patchy hair loss and significant scalp discomfort. These conditions occur when the immune system mistakenly targets hair follicles or surrounding skin, leading to inflammation, damage, and sometimes scarring. Examples include discoid lupus erythematosus (DLE), pemphigus foliaceus, frontal fibrosing alopecia, and dermatomyositis. These disorders may present with red or scaly plaques, blisters, or scarring, often resulting in patchy areas where hair fails to regrow.

Early intervention is critical for these diseases, as untreated inflammation can lead to permanent follicle destruction and irreversible bald patches. Dermatologists may recommend a combination of topical, oral, or immunosuppressive medications to control the immune response and minimize further hair loss. Patients who notice unusual scalp lesions, persistent redness, or rapidly expanding bald spots should seek prompt evaluation by a healthcare professional.

Timely diagnosis not only helps preserve existing hair but can also prevent systemic complications. For detailed information on autoimmune scalp diseases and treatment options, visit the American Academy of Dermatology’s guide to scarring alopecia and the Lupus Foundation of America’s resource on discoid lupus.

37. Chronic Skin Conditions (Eczema, Rosacea)

37. Chronic Skin Conditions (Eczema, Rosacea)
A close-up look at an inflamed scalp, highlighting red patches and irritation from eczema and rosacea flare-ups. | Generated by Google Gemini

Chronic skin conditions such as eczema (atopic dermatitis) and rosacea can negatively affect scalp health, leading to hair loss by disrupting the environment around hair follicles. Persistent inflammation, itching, and irritation characteristic of these disorders weaken the scalp’s protective barrier, making follicles more susceptible to damage and shedding. Eczema often presents as dry, red, and itchy patches that may become scaly or oozing, while rosacea typically causes redness, bumps, and sensitivity, primarily on the face but occasionally extending to the scalp.

Compared to psoriasis—which creates thick, silvery plaques—eczema is more likely to cause diffuse inflammation and intense itching, prompting scratching that physically dislodges hair. Psoriasis, on the other hand, results in more localized, sharply defined patches with underlying inflammation. Hair loss from eczema or rosacea is usually temporary if the inflammation is brought under control.

Management strategies include gentle hair care, medicated shampoos or topical steroids, and avoiding known irritants or allergens. Moisturizing the scalp and following a dermatologist-recommended treatment plan can help reduce inflammation and promote hair regrowth. For more on chronic skin conditions and scalp management, visit the American Academy of Dermatology’s eczema resource and the NHS guide to rosacea.

38. Medication Withdrawal

38. Medication Withdrawal
A prescription bottle lies open beside a small pile of shed hair, symbolizing the effects of medication withdrawal. | Generated by Google Gemini

Sudden withdrawal from certain medications can shock the hair growth cycle, triggering telogen effluvium and causing hair to shed in noticeable clumps. Medications commonly associated with this effect include oral contraceptives, antidepressants, corticosteroids, and some blood pressure drugs. When these drugs are stopped abruptly, the body experiences a sudden hormonal or biochemical shift, which disrupts the balance needed for healthy hair growth and prompts more follicles to enter the resting (telogen) phase.

For example, women discontinuing birth control pills often report increased hair shedding within two to three months. Similarly, individuals stopping antidepressants or corticosteroids may experience excessive shedding as their bodies adjust. Safe medication withdrawal typically involves a gradual tapering protocol, supervised by a healthcare provider, to minimize side effects and give the body time to adapt. Tapering helps reduce both systemic and hair-related withdrawal symptoms.

If you are considering stopping a medication and are concerned about hair loss or other withdrawal effects, consult your doctor or pharmacist for a safe discontinuation plan. For more about medication withdrawal and hair health, visit the American Academy of Dermatology’s medications and hair loss resource and the NHS medicines information.

39. Heavy Metal Exposure

39. Heavy Metal Exposure
A lab technician carefully prepares a strand of hair for heavy metals analysis, surrounded by scientific equipment and vials. | Generated by Google Gemini

Exposure to heavy metals such as lead, mercury, or arsenic can have toxic effects on the body, including damage to hair follicles and increased hair shedding. These metals disrupt cellular metabolism, induce oxidative stress, and impair the normal function of the integumentary system. Chronic or acute toxicity can result in diffuse hair thinning or the sudden appearance of hair coming out in clumps, sometimes accompanied by other systemic symptoms like fatigue, neurological changes, or gastrointestinal distress.

Occupational exposure is a common source of heavy metal toxicity, particularly for individuals working in industries such as battery manufacturing, mining, or chemical processing. Cases have been reported where workers developed hair loss following prolonged contact with contaminated materials or fumes. Environmental exposure (contaminated water, certain cosmetics, or herbal supplements) is also a potential risk.

If you suspect heavy metal exposure due to hair loss—especially if you have relevant occupational or environmental risk factors—discuss your symptoms with a healthcare provider. Blood, urine, or hair testing can help detect toxic levels and guide appropriate treatment or detoxification. For further information, see the CDC’s guide to occupational chemical exposure and the Poison Control resource on heavy metals.

40. Chronic Alcohol Use

40. Chronic Alcohol Use
A half-empty alcohol bottle stands beside a woman with dry, unhealthy hair cascading over her shoulders. | Generated by Google Gemini

Chronic alcohol use can significantly impair hair health by disrupting the absorption of essential nutrients, such as zinc, biotin, protein, and B vitamins, all of which are vital for hair growth and strength. Excessive alcohol consumption also increases oxidative stress and inflammation, which can further weaken hair follicles and accelerate shedding. Individuals who drink heavily are more likely to experience brittle, thinning hair that falls out in clumps, alongside other signs of nutritional deficiencies like skin changes and fatigue.

Moderate alcohol use—defined by most health organizations as up to one drink per day for women and two for men—typically has a less pronounced effect on nutrient absorption and overall hair health. However, heavy or prolonged drinking can deplete the body’s reserves of key vitamins and minerals, compounding hair loss and slowing regrowth. Recovery is possible: many people see improvement in hair density and quality after reducing alcohol intake, adopting a balanced diet, and supplementing any deficiencies under medical guidance.

If you are concerned about the impact of alcohol on your hair or notice persistent shedding, consider speaking with a healthcare provider about evaluation and support. For more details, visit the National Institute on Alcohol Abuse and Alcoholism’s resource on alcohol’s effects and the NHS alcohol support guide.

41. Smoking

41. Smoking
A woman with visibly thinning hair sits by a window, holding a lit cigarette between her fingers. | Generated by Google Gemini

Smoking has a well-established negative impact on hair health, primarily by constricting blood vessels and reducing blood flow to the scalp. This impaired circulation limits the delivery of oxygen and essential nutrients to hair follicles, increasing the risk of thinning and hair loss. Additionally, the toxins in cigarette smoke cause oxidative stress and inflammation, further damaging hair follicle cells and accelerating the aging process of the scalp.

Research demonstrates a clear association between smoking and both male and female pattern hair loss. A study published in the British Journal of Dermatology found that smokers were significantly more likely to experience moderate to severe hair loss compared to non-smokers. The cumulative effect of long-term smoking can make hair brittle, dull, and more likely to shed in clumps.

Quitting smoking not only improves cardiovascular and respiratory health but also supports better hair growth and scalp condition. Many former smokers report thicker, healthier hair after cessation. For support and motivation to quit, visit the Smokefree.gov and the NHS Quit Smoking page.

42. Over-Brushing or Aggressive Hair Handling

42. Over-Brushing or Aggressive Hair Handling
A woman gently brushes her hair, carefully tending to strands to prevent breakage and promote healthy hair care. | Generated by Google Gemini

Over-brushing or handling hair aggressively—such as forcefully towel drying, detangling, or styling—can cause significant mechanical damage that leads to breakage and clumps of hair falling out. When hair is wet, it is even more vulnerable, as the strands stretch and weaken more easily. Using brushes with rough bristles or yanking through tangles can snap hairs mid-shaft or pull them out from the root, especially in fine, curly, or chemically processed hair types.

The risk and extent of damage can vary by hair texture. Curly and coily hair is particularly prone to breakage and should be detangled gently with wide-tooth combs or fingers, ideally while conditioned and wet. Straight and fine hair, though less prone to tangling, can also suffer from over-brushing and should be styled with soft-bristle brushes or gentle combs. Rather than rubbing hair dry with a towel, gently blot or wrap it in a microfiber towel to minimize friction and damage.

Adopting gentle hair care practices—such as detangling from the ends upward, using leave-in conditioners, and limiting brushing to when necessary—can help preserve hair health. For more tips, visit the American Academy of Dermatology’s healthy hair habits guide and the NHS hair care tips.

43. Chronic Dehydration

43. Chronic Dehydration
A woman with dry, tousled hair reaches for a water bottle, highlighting the effects of dehydration. | Generated by Google Gemini

Chronic dehydration can have a profound effect on hair health, as water is essential for maintaining the strength, elasticity, and overall structure of each strand. When the body is inadequately hydrated, hair becomes dry, brittle, and more susceptible to breakage, leading to increased shedding and clumps of hair falling out. The scalp itself may also become dry and flaky, further compromising follicle health and hair growth.

Athletes, who often sweat heavily, are at risk of dehydration if they do not adequately replace lost fluids, but typically maintain better hydration habits than sedentary individuals. Sedentary people, on the other hand, may simply neglect to drink enough water throughout the day, not realizing the cumulative effect on their hair and scalp. Both groups benefit from conscious hydration: athletes need to replenish fluids lost through exercise, while everyone should aim for consistent water intake tailored to their body size, activity level, and climate.

Simple hydration tips include carrying a reusable water bottle, setting reminders to drink water, and consuming hydrating foods like fruits and vegetables. For more on the importance of hydration for hair and overall health, visit the CDC’s hydration guide and the NHS resource on water, drinks, and hydration.

44. Sleep Disorders

44. Sleep Disorders
A restless sleeper tosses and turns under rumpled sheets, illuminated by the soft glow of a bedside clock. | Generated by Google Gemini

Sleep disorders, such as insomnia or sleep apnea, can have a significant impact on hair health by disrupting the body’s natural regeneration cycles. During sleep, the body repairs tissues, balances hormones, and promotes cellular turnover—all essential processes for healthy hair growth. Chronic poor sleep or fragmented sleep can lead to elevated stress hormones (like cortisol), impaired nutrient absorption, and a shortened hair growth (anagen) phase, which may result in increased shedding or slower regrowth.

Cases of insomnia often accompany complaints of brittle, thinning hair or excessive shedding. Individuals who struggle with falling or staying asleep may notice their hair becomes less resilient, loses shine, and falls out more easily. Addressing sleep issues can therefore play a crucial role in restoring both overall health and optimal hair growth.

To improve sleep hygiene, establish a consistent bedtime routine, limit screen time before bed, avoid caffeine late in the day, and create a cool, dark, and quiet sleep environment. If sleep problems persist, consider consulting a sleep specialist. For more information on sleep and its effects on well-being, visit the Sleep Foundation’s guide to why we need sleep and the NHS resource on sleep and mental well-being.

45. Chronic Allergies

45. Chronic Allergies
A young woman sits with tissues in hand, rubbing her itchy scalp and wiping her runny nose from allergies. | Generated by Google Gemini

Chronic allergies, whether triggered by environmental factors such as pollen, dust mites, or pet dander, can lead to persistent low-grade inflammation throughout the body—including the scalp. This ongoing immune response may disrupt the normal hair growth cycle, weaken hair follicles, and cause increased shedding or clumps of hair to fall out. Inflammation can also make the scalp more sensitive, itchy, and prone to flaking, compounding the risk of hair loss.

Seasonal allergies, such as hay fever, often coincide with spikes in hair shedding during peak pollen months. People with year-round allergies may notice a more consistent pattern of scalp discomfort and diffuse thinning. Tracking symptoms—such as flare-ups in sneezing, itchy eyes, or skin rashes—alongside periods of increased hair loss can help identify allergy-related triggers.

Managing chronic allergies through antihistamines, minimizing allergen exposure, and maintaining good scalp hygiene can help reduce inflammation and protect hair health. If hair loss is severe or persistent, consult an allergist or dermatologist for comprehensive evaluation and treatment options. For more information, see the Asthma and Allergy Foundation of America’s allergy symptoms resource and the NHS guide to allergies.

46. Hair Shaft Abnormalities

46. Hair Shaft Abnormalities
A close-up view under a microscope reveals a damaged hair shaft with visible breakage along its delicate structure. | Generated by Google Gemini

Hair shaft abnormalities are rare inherited or acquired conditions that affect the structure of the hair, making it fragile and prone to breakage and clumping. These defects can occur as a result of genetic mutations or external damage from chemical treatments, excessive heat, or harsh grooming practices. One common example is trichorrhexis nodosa, where weak points or nodes form along the hair shaft, causing it to split and break easily under minimal stress. This leads to noticeable thinning, uneven hair length, and hair coming out in clumps, especially during brushing or washing.

Other inherited conditions, like monilethrix (beaded hair) and pili torti (twisted hair), result in abnormal hair shapes that are highly susceptible to breakage. Acquired forms may develop after repeated exposure to bleach, relaxers, or aggressive styling. Individuals experiencing persistent breakage, a rough or brittle texture, or an inability to grow hair beyond a certain length should consider seeing a dermatologist or trichologist for evaluation. Early diagnosis can help tailor hair care routines and minimize further damage.

For more on hair shaft disorders, visit the American Academy of Dermatology’s guide to hair shaft abnormalities and the DermNet NZ resource on trichorrhexis nodosa.

47. Scalp Sunburn or UV Damage

47. Scalp Sunburn or UV Damage
A woman applies sunscreen to her part line, protecting her scalp from sunburn under the bright summer sun. | Generated by Google Gemini

Scalp sunburn and prolonged UV exposure can weaken hair roots and lead to increased hair shedding. The scalp, often overlooked, is vulnerable to sunburn—especially where hair is thin or parted. UV radiation damages the skin, causing redness, pain, and inflammation that can disrupt the hair follicle environment. Severe burns may result in peeling, soreness, and temporary clumps of hair falling out as the damaged skin heals and sheds.

Comparing sun protection strategies, wearing a wide-brimmed hat, using a parasol, or styling hair to cover exposed areas are highly effective. For those with thinning hair or visible scalp, applying a broad-spectrum sunscreen designed for the scalp or a UV-protective spray is recommended. First-aid measures for sunburned scalp include gentle cleansing with cool water, avoiding harsh shampoos, applying soothing aloe vera gel, and taking over-the-counter pain relievers if necessary. Avoid picking at peeling skin or brushing vigorously, as this can worsen shedding.

Persistent or severe scalp burns should be evaluated by a healthcare provider. For more guidance, see the American Academy of Dermatology’s sun protection tips and the NHS guide to sunburn care.

48. Parasitic Infestations (e.g., Lice)

48. Parasitic Infestations (e.g., Lice)
Tiny lice are visible clinging to hair strands on a scalp, showing how these parasites can contribute to hair loss. | Generated by Google Gemini

Parasitic infestations, such as head lice or mites, can lead to significant scalp irritation and subsequent hair loss. Lice feed on blood from the scalp, causing intense itching, inflammation, and small red bumps. Scratching in response to this irritation can physically pull out hair, leading to clumps of shedding and sometimes secondary infections. Mites, such as those responsible for scabies, burrow into the scalp, causing similar symptoms and hair breakage due to persistent scratching.

Outbreaks are common in close-contact environments like schools and summer camps, where children may share hats, combs, or bedding. Teachers and parents might notice children frequently scratching their heads or see visible nits (lice eggs) attached to hair shafts near the scalp. Prompt diagnosis and treatment are essential to prevent spread and minimize hair loss.

Effective eradication involves using medicated shampoos or topical treatments specifically designed for lice or mites, thoroughly cleaning personal items, and notifying close contacts or institutions. Manual removal of nits with a fine-tooth comb is often necessary. For more on detection and management, visit the CDC’s head lice resource and the NHS guide to head lice and nits.

49. Rare Tumors of the Scalp

49. Rare Tumors of the Scalp
A noticeable, hairless lump protrudes from the scalp, highlighting an abnormal tumor on the top of the head. | Generated by Google Gemini

Rare tumors of the scalp, whether benign (such as pilomatricomas or sebaceous cysts) or malignant (such as basal cell carcinoma, squamous cell carcinoma, or melanoma), can disrupt normal hair growth by physically altering the scalp’s structure and damaging hair follicles. These growths may present as firm lumps, nodules, or ulcerated lesions, sometimes accompanied by localized hair loss, scaling, or persistent sores that do not heal. In some cases, a tumor may compress or invade the roots of hair follicles, resulting in patchy bald spots or clumps of hair falling out.

Case examples include individuals noticing a slowly enlarging, painless bump on the scalp that eventually becomes tender or starts to bleed, or patients with a non-healing sore surrounded by hair thinning. Red-flag symptoms warranting immediate evaluation include rapidly growing masses, lesions that bleed or ooze, color changes, or any scalp lump persisting for more than a few weeks.

Early detection and treatment are critical, as malignant tumors can pose serious health risks. If you detect an unusual lesion on your scalp with associated hair loss, consult a dermatologist promptly. For more information, see the American Cancer Society’s page on skin cancers and the NHS resource on skin cancer symptoms.

50. Idiopathic (Unknown Cause)

50. Idiopathic (Unknown Cause)
A worried person sits pensively beside a large question mark, reflecting uncertainty about an unknown cause. | Generated by Google Gemini

Despite comprehensive medical evaluation, there are cases where the cause of hair loss remains unidentified—classified as idiopathic hair loss. Blood tests, scalp biopsies, and detailed histories may yield no conclusive answers, leaving patients and doctors puzzled. This can be frustrating, as individuals may experience shedding in clumps or gradual thinning with no obvious triggers, underlying illnesses, or family history. Such cases highlight the complexity of hair biology and the influence of subtle, perhaps still-unknown, factors.

Fortunately, spontaneous recovery is not uncommon. Some people regrow their hair within several months without any targeted intervention, possibly due to the natural resolution of a transient imbalance or stressor that went undetected. Ongoing monitoring is essential: patients are often advised to track changes, maintain healthy habits, and schedule periodic follow-ups with their dermatologist. If new symptoms arise, they should be reported promptly, as they may provide fresh clues for diagnosis.

The idiopathic category underscores the importance of patience and self-care during the recovery period. For more on unexplained hair loss and support, visit the American Academy of Dermatology’s guide to unexplained hair loss and the NHS overview on hair loss.

Conclusion

Conclusion
A doctor carefully examines a patient’s hair while reviewing a medical checklist during a thorough consultation. | Generated by Google Gemini

Experiencing hair loss in clumps is often a sign that requires prompt attention, as it may signal an underlying health issue or environmental trigger. Early evaluation by a healthcare provider or dermatologist can help identify the cause and prevent further loss. Practical next steps include scheduling a specialist visit, undergoing recommended lab tests, and keeping a detailed record of symptoms and patterns. Taking these actions increases the likelihood of effective treatment and recovery. For more information on when to seek help and how to prepare, visit the American Academy of Dermatology’s guide to seeing a dermatologist and the NHS resource on hair loss.

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