What Your Fingernails Are Trying to Tell You About Your Health

1. Clubbing

Clubbing refers to the noticeable enlargement and rounding of the fingertips, accompanied by an increased curvature of the nails. This change occurs over time and often signals underlying health issues rather than being a harmless cosmetic variation. The process involves the soft tissue beneath the nail bed swelling, causing the nail to become more convex both side-to-side and front-to-back. Clubbing is most commonly associated with chronic lung diseases, such as lung cancer, cystic fibrosis, or pulmonary fibrosis, but can also indicate heart conditions like congenital heart disease or infective endocarditis.
The exact mechanism is not fully understood, but it is believed to result from increased blood flow to the fingertips due to chronic low oxygen levels in the blood. Early detection is vital because clubbing can be an early or even the first sign of a serious systemic illness.

Noticeable swelling of the fingertips
Increased curvature of the nail (both longitudinally and transversely)
Softening of the nail bed
Loss of the normal angle between the nail and nail bed

If you observe these changes, consult a healthcare professional to investigate potential underlying causes. For more information, visit the Cleveland Clinic.

2. Beau’s Lines

Beau’s lines are deep, horizontal grooves or indentations that run across the fingernails, often spanning from one side of the nail to the other. These lines form when nail growth is temporarily interrupted, usually as a result of a significant physical or emotional stressor. This interruption could be triggered by severe illness, high fever, surgery, uncontrolled diabetes, or even trauma to the nail itself. Infections such as mumps, pneumonia, or severe COVID-19 have also been linked to Beau’s lines.
The appearance of Beau’s lines reflects a distinct pause in nail growth, which can be dated by examining how far the groove is from the nail bed, often helping to determine when the stressful event occurred. While a single groove may signify a one-time event, multiple lines can indicate repeated or ongoing health challenges.

Noticeable horizontal ridges or grooves
Usually affect multiple nails simultaneously
May be accompanied by brittle or thinning nails

If you notice Beau’s lines, especially on several nails, it is important to consult a healthcare provider. They can help identify underlying illnesses that may require attention. Learn more about Beau’s lines from the Harvard Health Publishing.

3. Spoon Nails (Koilonychia)

Spoon nails, medically termed koilonychia, are characterized by nails that become abnormally thin, soft, and curve upwards at the edges, creating a concave or spoon-like appearance. This distinctive shape is most commonly associated with iron deficiency anemia, a condition where the body lacks sufficient healthy red blood cells due to inadequate iron. Other causes may include chronic blood loss, malnutrition, or exposure to certain chemicals.
The development of spoon nails is not just a cosmetic concern—it can be an early warning sign of underlying problems with iron absorption or chronic blood loss. People with koilonychia may also report brittle nails or cracking. If you notice your nails becoming unusually thin or curving upward, it’s advisable to seek medical evaluation and have your iron levels checked. Prolonged iron deficiency can lead to fatigue, weakness, and other serious complications if not addressed.

Thin, soft nails with a concave shape
Nail edges that lift upward
Possible brittleness or splitting

For more information on spoon nails and iron deficiency anemia, visit the Mayo Clinic.

4. Pitting

Pitting refers to the presence of small, pinpoint depressions or dents across the surface of the nails. These shallow pits may appear randomly or in clusters, and they often signal changes happening beneath the nail plate. One of the most frequent causes of nail pitting is psoriasis, a chronic autoimmune skin disorder that can also affect the joints, leading to psoriatic arthritis. Around 50% of people with psoriasis experience some nail involvement, making this an important sign to watch for.
In addition to pitting, nails may become discolored, thickened, or brittle. Monitoring your nails for these subtle changes can provide early clues about potential skin or joint conditions. If you observe persistent pitting, check your skin for red, scaly patches or your joints for swelling and pain. Keeping a record of such symptoms can help your healthcare provider make a more accurate diagnosis.

Small, shallow dents or pits on the nail surface
Possible discoloration or thickening
Association with skin or joint changes

For more details on nail pitting and its connection to psoriasis, see the National Psoriasis Foundation.

5. Terry’s Nails

Terry’s nails are characterized by a striking appearance: the majority of the nail plate turns white while a narrow band of pink or reddish-brown remains at the tip. This condition often affects most or all fingernails simultaneously. Terry’s nails are most commonly associated with liver disease, particularly cirrhosis, but can also be seen in people with congestive heart failure, diabetes, or kidney failure.
The underlying mechanism involves changes in the nail bed’s blood supply, often as a result of chronic illness. Although the nails themselves may not be painful, their dramatic change in color is a red flag for systemic health concerns. If you notice this pattern, especially in conjunction with symptoms like jaundice, swelling, or fatigue, it is important to consult your healthcare provider for a thorough liver health evaluation.

White nails with a narrow pink or brown band at the tip
Usually affects most fingernails
Commonly linked to chronic liver conditions

For a comprehensive overview of Terry’s nails and their medical implications, visit the Mount Sinai Health Library.

6. Muehrcke’s Lines

Muehrcke’s lines present as pairs of white, horizontal lines running parallel to the lunula (the crescent-shaped area at the nail base). Unlike grooves or ridges, these lines are not raised and do not move as the nail grows—they are a reflection of changes in the nail bed, not the nail plate itself. Muehrcke’s lines are most commonly linked to low levels of albumin, a vital blood protein. This is often caused by protein deficiency, severe malnutrition, or underlying kidney disease that impairs protein retention.
If you notice these double white lines on several nails, especially when accompanied by swelling, fatigue, or other symptoms of malnutrition or kidney problems, prompt medical evaluation is important. Blood tests can help determine if you have low protein levels or underlying organ dysfunction.

Two or more white lines running horizontally across the nail
Lines remain stationary as the nail grows
Associated with protein deficiency or kidney disease

To learn more about Muehrcke’s lines and their significance, consult the National Institutes of Health (NIH).

7. Leukonychia

Leukonychia refers to the presence of white spots, streaks, or patches on the nails. The most common type, punctate leukonychia, appears as small white dots and is usually the result of minor trauma to the nail matrix, such as bumping or pinching the finger. This type is harmless and typically grows out with the nail over time. However, when larger white streaks or bands appear across several nails, or if the discoloration does not grow out, it may signal an underlying health issue.
Systemic causes of leukonychia include zinc deficiency, fungal infections, or, less commonly, conditions such as liver disease or arsenic poisoning. If you notice persistent or widespread white discoloration, especially if accompanied by other symptoms like fatigue, digestive changes, or skin rashes, it’s important to seek medical advice for further evaluation.

Small white spots (usually from trauma)
Larger white streaks or bands (potentially systemic)
Monitor for additional symptoms

For more information about leukonychia and its possible causes, visit the DermNet NZ.

8. Yellow Nail Syndrome

Yellow Nail Syndrome is a rare but significant condition marked by slow-growing, thickened nails that take on a yellow or greenish hue. The nails may also become excessively curved and, in some cases, detach from the nail bed. This syndrome is closely associated with problems in the lymphatic system, such as lymphedema (swelling caused by lymphatic fluid retention), as well as chronic respiratory conditions including bronchiectasis and chronic sinusitis.
People with Yellow Nail Syndrome may also notice their nails stop growing, become brittle, or develop ridges. Because this nail change frequently signals underlying systemic conditions affecting fluid balance or lung health, it should never be ignored.

Thickened, yellow or greenish nails
Slow nail growth and increased curvature
Possible swelling of hands or feet (lymphedema)
Chronic respiratory symptoms (cough, sinus issues)

If you observe these distinct nail changes, especially alongside breathing difficulties or limb swelling, it is important to consult a healthcare provider for a thorough evaluation. For more information, visit the National Institutes of Health: Yellow Nail Syndrome.

9. Onycholysis

Onycholysis occurs when the nail separates from the nail bed, creating a gap that may appear white, yellow, or greenish. This condition can affect multiple nails and is often painless unless infection sets in. While trauma or fungal infections are common culprits, onycholysis is also frequently linked to thyroid disorders—both hyperthyroidism and hypothyroidism can disrupt normal nail growth and attachment.
If you notice your nails lifting from the bed without a clear cause, consider screening for thyroid dysfunction, especially if you have other symptoms such as unexplained weight changes, fatigue, or changes in hair and skin texture.

Nail detachment, starting at the tip and progressing toward the cuticle
Discoloration beneath the separated area
Increased risk of secondary fungal or bacterial infection

To care for affected nails, keep them trimmed, avoid harsh chemicals, and protect your hands from repeated wetting or trauma. If onycholysis persists or worsens, consult an endocrinologist for further evaluation. For more about onycholysis and thyroid health, visit the American Academy of Dermatology.

10. Splinter Hemorrhages

Splinter hemorrhages are tiny, thin, red or brown lines that run vertically beneath the nail plate, resembling splinters embedded in the nail. These streaks result from small areas of bleeding under the nail, often caused by trauma such as bumping or pinching a finger. In most cases, a single splinter hemorrhage is harmless and will grow out with the nail.
However, when multiple streaks appear across several nails without a clear cause, it can be a warning sign of more serious conditions, such as endocarditis—an infection of the heart valves. Other possible associations include vasculitis or certain autoimmune diseases.

Thin, red or brown streaks running from the cuticle to the tip
May affect one or multiple nails
Often painless but should be monitored

Prompt medical evaluation is crucial if splinter hemorrhages are accompanied by fever, heart murmurs, or unexplained fatigue, as these could indicate underlying systemic disease. For more about splinter hemorrhages and when to seek help, visit Mount Sinai Health Library.

11. Brown or Black Streaks

Brown or black streaks running lengthwise along the nail can be alarming, especially when they appear suddenly or change over time. While some cases are benign—such as ethnic pigmentation, moles, or trauma-induced changes—certain patterns warrant urgent attention. The most serious concern is subungual melanoma, a rare but aggressive form of skin cancer that can originate beneath the nail plate.
Warning signs of melanoma include a single dark streak that widens, darkens, or develops irregular borders, or if the pigment spreads onto the surrounding skin (known as Hutchinson’s sign). Other changes to watch for include nail splitting, bleeding, or persistent discoloration that cannot be explained by injury.

Vertical brown or black lines along the nail
Widening, irregular, or changing streaks
Pigmentation spreading to the nail fold

Prompt dermatological evaluation is essential for any new, changing, or unexplained dark streaks. Early detection of subungual melanoma can be life-saving. For more on nail streaks and skin cancer, visit the Skin Cancer Foundation.

12. Brittle Nails

Brittle nails are a common complaint, characterized by nails that split, crack, or peel easily. While frequent hand washing, exposure to harsh chemicals, or dry environments are the most typical causes, persistent brittleness can sometimes signal underlying health issues, such as thyroid disease—especially hypothyroidism—or nutritional deficiencies like low biotin or iron levels.
Pay attention if your nails are consistently fragile despite proper care, or if you also experience symptoms like fatigue, hair loss, or unexplained weight changes. Addressing environmental triggers is the first step, but ongoing brittleness may justify further medical evaluation, particularly for thyroid function or nutritional status.

Splitting, peeling, or crumbling nails
Worsens with water exposure or chemical irritants
May be linked to systemic illness

To care for brittle nails: moisturize your hands and nails regularly, avoid prolonged contact with water and detergents, use gloves when cleaning, and keep nails trimmed. For additional guidance, visit American Academy of Dermatology: Brittle Nails.

13. Thickened Nails

Thickened nails are often a result of fungal infections, such as onychomycosis, or repeated trauma and injury to the nail bed. Fungal infections thrive in warm, moist environments and can cause the nails to become yellow, crumbly, and difficult to trim. This condition is similar to athlete’s foot, which affects the skin between the toes but can also spread to the nails, making both problems more challenging to treat.
Other causes of nail thickening include psoriasis, circulation problems, or simply aging. While thickened nails are not usually painful initially, they can become uncomfortable and increase the risk of secondary infections if left untreated.

Nails become hard, yellowish, and difficult to cut
May be accompanied by flaking or separation from the nail bed
Common in people with athlete’s foot or poor foot hygiene

To help prevent thickened nails, keep your feet clean and dry, wear breathable shoes, and avoid sharing nail tools. For more prevention and treatment tips, see Centers for Disease Control and Prevention: Nail Infections.

14. Blue Nails

Blue nails, medically known as nail cyanosis, appear when the nail beds take on a bluish or purplish tint. This discoloration is usually a sign that your blood is not carrying enough oxygen to the fingertips. The underlying causes can range from temporary factors—such as exposure to cold—to serious medical conditions affecting the heart or lungs, like chronic obstructive pulmonary disease (COPD), congenital heart defects, or severe asthma.
When blue nails occur suddenly or are accompanied by symptoms such as shortness of breath, chest pain, confusion, or overall weakness, it may indicate a medical emergency. Chronic cyanosis, especially when paired with clubbing or other nail changes, should always prompt a thorough evaluation by a healthcare provider.

Bluish or purplish tint to the nail beds
Associated with cold, heart, or lung conditions
Monitor for breathing difficulties or chest symptoms

Seek urgent care if you experience blue nails with other signs of low oxygen. For more information on cyanosis and related health risks, visit Mayo Clinic: Cyanosis.

15. Red or Purple Nails

Red or purple nails can indicate underlying problems with blood flow or the blood vessels beneath the nail bed. Sometimes, trauma or cold exposure can temporarily cause this discoloration, but persistent reddish or purplish hues may signal more serious conditions. Vascular disorders, such as Raynaud’s phenomenon or vasculitis, can disrupt normal blood supply, resulting in nail color changes. In rare cases, bleeding disorders or platelet abnormalities may also manifest as red or purple discoloration due to tiny blood leaks under the nails.
If you notice these changes, especially if accompanied by other signs like easy bruising, unexplained bleeding, or frequent nosebleeds, it is important to consult a hematologist or your primary care physician. Evaluation may include blood tests to assess clotting function and rule out systemic vascular or hematologic disorders.

Persistent reddish or purplish nail beds
May be linked to blood vessel or clotting problems
Monitor for additional bleeding or bruising symptoms

To learn more about vascular and bleeding disorders affecting nails, visit American Society of Hematology: Blood Disorders.

16. White Nails (True Leukonychia)

True leukonychia describes a condition where the entire nail plate turns completely white, sometimes obscuring the natural pinkish color of the nail bed beneath. Unlike isolated spots or streaks, this whitening usually affects most or all of the nail surface. While trauma or fungal infections can cause partial whitening, true leukonychia is often linked to systemic illnesses, particularly liver disease (such as cirrhosis) or chronic kidney disease.
The underlying mechanism may relate to changes in protein metabolism or blood flow in the nail bed due to organ dysfunction. If you notice complete whitening of your nails—especially if accompanied by symptoms like swelling, jaundice, or persistent fatigue—request a thorough medical evaluation. Blood tests for liver and kidney function are crucial to rule out or diagnose a serious underlying condition.

Entire nail plate appears uniformly white
May occur alongside other systemic symptoms
Commonly associated with liver or kidney disorders

To better understand true leukonychia and its connection with systemic disease, visit the Mount Sinai Health Library.

17. Green Nails

Green nails are most often caused by a bacterial infection, specifically with Pseudomonas aeruginosa. This organism thrives in damp or moist environments and can invade the space between the nail plate and nail bed, leading to a distinctive greenish discoloration. People who frequently have their hands submerged in water—such as dishwashers, healthcare workers, or those who wear artificial nails—are especially prone to this condition, commonly called “green nail syndrome.”
The infection is typically painless, but the color can range from pale green to deep blue-green. Occasionally, the nail may also thicken or separate from the nail bed. Good hygiene practices are crucial: keep nails dry, avoid prolonged exposure to water, and disinfect nail tools regularly. If you suspect a pseudomonas infection, consult your healthcare provider for appropriate topical or oral treatment, as untreated cases can persist or spread.

Green or blue-green discoloration beneath the nail
Common after frequent water exposure or artificial nails
Prevent with good hand hygiene and keeping nails dry

For more about green nail syndrome and prevention, visit the Centers for Disease Control and Prevention: Green Nail Syndrome.

18. Nail Lifting (Onychomadesis)

Onychomadesis is a condition where the nail plate separates and eventually sheds from the nail bed, starting at the base (proximal end) and moving outward. This dramatic change is often triggered by a temporary halt in nail growth, usually after a severe systemic illness, high fever, hand-foot-and-mouth disease, or significant infection. The interruption at the nail matrix causes the old nail to stop growing and eventually detach, making way for new nail growth beneath.
Nail shedding can affect one or several nails and may be alarming, but it typically signals a past event rather than ongoing disease. Keeping track of when nail lifting occurs can help correlate it with recent illnesses or major stressors, as the timing often corresponds with events from weeks or even months prior.

Nail plate separates from the base and sheds
Common after severe illness, infection, or trauma
Timeline of nail loss can reflect previous health events

If you experience onychomadesis, discuss recent health history with your healthcare provider and monitor for regrowth of new, healthy nails. For more information, visit the DermNet NZ: Onychomadesis.

19. Vertical Ridges

Vertical ridges are raised lines that run from the cuticle to the tip of the nail. These ridges are commonly seen as part of the natural aging process and, in most cases, are harmless. As we get older, nail cell turnover slows, resulting in more pronounced lines that are similar to wrinkles on the skin. However, when vertical ridges become suddenly more noticeable, deeper, or are accompanied by other nail changes, they may signal nutritional deficiencies, such as a lack of magnesium, vitamin B12, or iron.
If you notice additional symptoms like brittle nails, discoloration, or unexplained fatigue, it’s wise to review your diet and consider consulting a healthcare provider. Addressing possible deficiencies often involves dietary adjustments or supplements. Persistent or worsening changes should always prompt further evaluation to rule out underlying systemic conditions.

Fine or pronounced lines running lengthwise on the nail
Common with aging, but can indicate nutritional issues
Monitor for associated symptoms or sudden changes

For more on healthy nail structure and diet, visit Harvard T.H. Chan School of Public Health: Vitamin B12.

20. Nail Discoloration

Nail discoloration can present as yellow, brown, green, blue, or even black changes on the nail plate or bed. While some color shifts are benign—such as staining from nail polish, tobacco, or certain foods—other changes may point to underlying medical conditions. For example, yellowing often suggests fungal infection or respiratory problems, while blue or purple hues may indicate poor oxygenation or vascular disorders.
It’s important to distinguish between harmless staining and more concerning changes. If discoloration appears suddenly, persists, affects multiple nails, or is accompanied by pain, swelling, or changes in nail texture, seek professional evaluation. A dermatologist or healthcare provider can help determine the cause through examination and, if needed, laboratory tests.

Temporary staining (from dyes, polish, or habits)
Persistent or spreading color changes
Associated symptoms may warrant medical review

For more about nail discoloration and when it signals a medical problem, see American Academy of Dermatology: Nail Discoloration.

21. Biting and Chewed Nails

Nail biting, or onychophagia, is a common habit that often begins in childhood and can persist into adulthood. While some people bite their nails out of boredom or stress, frequent or severe nail biting may signal underlying mental health concerns, such as anxiety disorders or obsessive-compulsive disorder (OCD). Chronic nail biting can damage the nail bed, lead to infection, and even affect dental health.
If you find it difficult to stop biting your nails, consider keeping a journal to track triggers or stressful situations. Simple interventions—such as keeping nails trimmed, using bitter-tasting nail polish, or occupying your hands with other activities—can help break the cycle. In more persistent cases, cognitive-behavioral therapy (CBT) has been shown to be effective at addressing the underlying psychological drivers.

Physical damage to nails and cuticles
Potential link to anxiety or OCD
Behavioral and psychological approaches for support

For more on the connection between nail biting and mental health, visit Anxiety.org: Nail Biting and Anxiety.

22. Curved (Convex) Nails

Curved or convex nails refer to nails that arch more than usual, either from side to side or from the base to the tip. While a gentle curvature can be normal, excessive convexity may suggest an underlying health issue. Some people are born with naturally curved nails, a harmless congenital trait. However, acquired changes in nail shape—such as increased convexity developing over time—may be linked to systemic conditions.
Potential causes include respiratory issues (such as chronic obstructive pulmonary disease), cardiovascular diseases, or metabolic disorders. Abnormal curvature can also result from trauma, chronic infection, or certain medications. If you notice your nails becoming more curved, especially alongside symptoms like shortness of breath, fatigue, or swelling, it’s important to seek medical evaluation to rule out serious underlying causes.

Exaggerated arch or “parrot beak” appearance
May be congenital or acquired later in life
Monitor for changes in nail shape or associated health symptoms

For more about nail shape abnormalities and when to investigate further, visit the National Library of Medicine: Nail Abnormalities.

23. Ingrown Nails

Ingrown nails occur when the edge or corner of a nail grows into the surrounding skin, often causing pain, redness, swelling, and sometimes infection. The big toe is most commonly affected, but any finger or toenail can become ingrown. Common causes include improper nail trimming (such as cutting nails too short or rounding the edges), wearing tight shoes, or trauma to the nail area. Genetics and certain foot shapes can also predispose individuals to this condition.
Signs of infection include increased redness, warmth, pus, or a throbbing sensation around the nail. Early intervention is important to prevent complications, especially for people with diabetes or poor circulation.

Sore, swollen skin beside the nail
Redness and possible pus formation
Pain intensified by pressure or walking

To prevent ingrown nails, cut nails straight across, avoid rounding the corners, and wear well-fitting shoes. If infection or significant discomfort develops, consult a healthcare provider or podiatrist. For step-by-step nail care instructions, see the American Academy of Dermatology: Ingrown Nails.

24. Nail Splitting (Onychoschizia)

Nail splitting, also known as onychoschizia, is a common problem where nails split or peel into layers, typically at the tips. This condition is often caused by repeated wetting and drying, frequent exposure to soaps, detergents, or solvents, and insufficient hydration. Environmental factors play a major role—cold, dry weather, or frequent hand washing can strip moisture from both nails and skin, leading to brittleness and splitting.
Other contributing factors include nutritional deficiencies (such as low biotin or iron), aging, and the use of harsh nail products like acetone-based polish removers. Moisturizing and gentle nail care are key to prevention and recovery.

Nails peel or split into layers at the tips
Common after water, chemical, or weather exposure
May be linked to dehydration or nutritional gaps

To help prevent nail splitting, apply a rich moisturizer to your nails and cuticles daily, wear gloves during household chores, and limit use of harsh chemicals. For more self-care advice, visit Harvard Health: Nail Care Tips.

25. Horizontal Ridges (Mees’ Lines)

Mees’ lines appear as distinct, white, horizontal bands that run parallel to the lunula across the entire nail plate. Unlike Beau’s lines, which are grooves, Mees’ lines do not indent the nail and move outward as the nail grows. These lines are most famously associated with arsenic or heavy metal poisoning, but can also develop after certain infections, chemotherapy, or severe systemic illnesses.
The presence of Mees’ lines should prompt a careful review of recent exposure history. Possible sources include contaminated water, occupational hazards, or accidental ingestion of toxic substances. Multiple nails are typically affected, and the timing of the lines can help estimate when the exposure occurred.

White, horizontal bands spanning the nail width
Associated with arsenic, thallium, or heavy metal poisoning
May follow severe illness or chemotherapy

If you notice unexplained horizontal white bands and have concerns about possible toxin exposure, seek prompt medical evaluation and share your full history with your provider. For more on Mees’ lines and heavy metal toxicity, see the CDC: Arsenic.

26. Puffy Nail Folds (Paronychia)

Puffy nail folds, medically known as paronychia, are characterized by redness, swelling, and tenderness of the skin surrounding the nail. Acute paronychia is usually caused by a bacterial or fungal infection, often resulting from nail biting, manicures, or frequent exposure to moisture. Chronic paronychia, on the other hand, may signal underlying conditions such as eczema or autoimmune diseases like lupus or scleroderma.
Symptoms include a swollen, sometimes pus-filled area at the base or sides of the nail, discomfort when pressing on the area, and possible changes in the nail shape if the condition persists. Good hygiene and prompt care are crucial—soak the affected finger in warm water, keep the area dry, and avoid irritants. For persistent or worsening swelling, or if pus develops, seek medical attention as antibiotics or antifungals may be needed.

Red, swollen, and tender skin around the nail
May be caused by infection, trauma, or autoimmune conditions
Soak, keep dry, and seek care if symptoms worsen

For more information on paronychia and nail fold care, visit American Academy of Dermatology: Paronychia.

27. Crumbling Nails

Crumbling nails are characterized by a fragile, rough nail surface that easily breaks down into small pieces or flakes. This type of nail damage is frequently associated with fungal infections (onychomycosis), which can cause the nail to become thick, yellow, and brittle before it starts to crumble. Psoriasis, a chronic autoimmune skin disorder, can also break down the nail’s structure, leading to a similar crumbled appearance and sometimes pitting or discoloration.
Crumbling nails should not be ignored, as they can signal underlying infection or systemic disease. Over-the-counter antifungal treatments may be helpful in mild cases, but prescription medications are often needed for persistent infections or when psoriasis is involved. If your nails are consistently crumbling, or if you have other symptoms such as skin changes or joint pain, consult a dermatologist for accurate diagnosis and targeted therapy.

Rough, fragile, or flaky nail surface
Often linked to fungal infections or psoriasis
Dermatology evaluation recommended for persistent symptoms

For a thorough overview of nail surface disorders and treatment options, visit American Academy of Dermatology: Nail Fungus.

28. Nail Detachment After Injury

Nail detachment following trauma—such as slamming a finger in a door, dropping something heavy, or direct blows—can result in partial or complete separation of the nail from the nail bed. This process, called traumatic onycholysis, often looks alarming but is a fairly common result of acute injury. The nail may become discolored (red, purple, or black) due to bleeding underneath, and it may loosen and fall off over the following days or weeks.
Healing timelines vary: a new fingernail can take three to six months to fully regrow, while toenails may require up to a year. Keeping the area clean and protected is important to prevent infection. If there is significant pain, swelling, persistent bleeding, or if the injury involved crushing force, seek medical care to rule out underlying fractures or damage to the nail matrix.

Nail separation or loss after trauma
Bruising or bleeding under the nail
Regrowth usually occurs, but check for bone injury if severe

For more on traumatic nail injuries and proper care, visit Mount Sinai Health Library: Nail Injury.

29. Nail Weakness After Illness

Nail weakness is commonly observed after recovery from a severe illness, high fever, or significant stress to the body. During periods of systemic illness, the body may temporarily halt nail growth to conserve resources, leading to thinner, softer, and more fragile nails that are prone to breaking or splitting as they grow out. This effect might become noticeable weeks or even months after the illness, as the affected nail segment grows forward from the cuticle.
Supporting nail regrowth involves a balanced diet rich in proteins, vitamins (especially biotin and B vitamins), and minerals like zinc and iron. Keeping nails trimmed, moisturized, and protected from trauma or harsh chemicals also promotes recovery.

Thinning, soft, or brittle nails post-illness
Growth may recover over several months
Nutrition and gentle care aid regrowth

If nail weakness persists long after recovery, or if you notice additional symptoms, consult a healthcare provider to rule out ongoing nutritional deficiencies or other underlying issues. For more on recovery and nail health, visit Medical News Today: Nail Changes and Health.

30. White Spots After Manicures

White spots or patches that appear on the nails after a manicure are often the result of superficial trauma or irritation to the nail plate. Vigorous buffing, aggressive cuticle pushing, or frequent use of harsh nail polish removers can disrupt the surface cells, leading to these temporary, chalky marks. Prolonged or repeated exposure to nail polish, especially without breaks, can also weaken the nail’s protective barrier, making white spots more likely.
Fortunately, these cosmetic changes are rarely harmful and usually grow out as the nail advances. To prevent further damage, practice gentle nail care: avoid scraping or over-buffing, use acetone-free polish remover, and give your nails regular breaks from polish. Always moisturize nails and cuticles after removing polish or washing hands.

Superficial, chalky white marks after manicuring
Often due to buffing or harsh removers
Gentle techniques and nail hydration promote recovery

For advice on safe nail care and avoiding cosmetic damage, see American Academy of Dermatology: Nail Care Tips.

31. Nail Growth Rate Changes

Nail growth rate is a subtle indicator of overall health and nutritional status. Healthy fingernails typically grow about 3 millimeters per month, while toenails grow more slowly. Factors such as age, circulation, hormone levels, and seasonal changes can all influence this rate. However, when nails grow noticeably slower than usual, it may signal underlying problems such as hypothyroidism, poor circulation, severe nutritional deficiencies, or chronic systemic illness.
Diet plays a key role in nail growth, with protein, biotin, zinc, and iron all contributing to healthy nail formation. Illness, stress, or medication side effects can also cause temporary growth delays. If you notice persistent or unexplained slow nail growth—especially if accompanied by brittle, discolored, or ridged nails—consult a healthcare professional to evaluate for thyroid dysfunction, anemia, or vascular issues.

Normal fingernail growth: about 3 mm/month
Slowed growth may reflect underlying health concerns
Nutrition and circulation are key factors

For more on nail growth and its connection to health, visit National Library of Medicine: Nail Growth.

32. Lines From Chemotherapy

Chemotherapy can have a significant impact on the nails, often causing visible changes such as dark pigmentation, white bands, or pronounced horizontal ridges (Beau’s lines or Mees’ lines). These nail changes occur because chemotherapy temporarily disrupts nail growth at the matrix, resulting in lines or color changes that move outward as the nail grows. Some medications may also make nails more brittle, cause them to separate from the nail bed, or lead to discoloration of the cuticle or surrounding skin.
Supportive care during treatment includes keeping nails trimmed, avoiding trauma or harsh chemicals, and moisturizing nails and cuticles regularly. Wearing gloves for household tasks and protecting nails from trauma can help prevent further damage. Most chemotherapy-induced nail changes are temporary and improve after treatment ends, but any signs of pain, infection, or severe nail loss should be reported to your oncology team.

Horizontal ridges, dark bands, or white lines on nails
Brittleness or separation from the nail bed
Supportive nail care and gentle handling recommended

For more on nail changes during cancer treatment and supportive strategies, visit American Cancer Society: Nail Changes.

33. Half-and-Half Nails (Lindsay’s Nails)

Half-and-half nails, also known as Lindsay’s nails, are characterized by a distinctive two-toned appearance: the proximal half of the nail (closest to the cuticle) is pale or white, while the distal half (toward the tip) is pink, red, or brown. This striking pattern is most commonly associated with chronic kidney disease or renal failure. Around 20-50% of patients with advanced kidney disease develop this nail change.
The exact mechanism behind Lindsay’s nails is not fully understood, but it is believed to involve changes in blood flow and protein metabolism due to impaired kidney function. If you notice this type of nail discoloration, especially if you have additional symptoms like swelling, fatigue, or changes in urination, it is important to request a renal evaluation, including blood and urine tests.

Pale or white color at the nail base
Pink, red, or brown band at the nail tip
Strongly linked to chronic kidney disease

For more information on Lindsay’s nails and kidney health, see National Kidney Foundation: Nails and Kidney Disease.

34. Brittle Nails and Menopause

Brittle nails are a frequent concern for women entering menopause, a life stage marked by hormonal fluctuations that typically begins between ages 45 and 55. The decline in estrogen during menopause affects the body’s ability to retain moisture, not just in the skin and hair, but also in the nails. This can lead to nails that split, peel, or break easily, often coinciding with other menopausal symptoms such as hot flashes and dry skin.
Self-care strategies for brittle nails during menopause include moisturizing nails and cuticles daily, using gentle nail care products, and wearing gloves during household chores to reduce chemical and water exposure. A balanced diet rich in protein, healthy fats, and vitamins (especially biotin and vitamin E) can also help strengthen nails. If nail brittleness is severe or accompanied by other unexplained health changes, consult a healthcare provider to rule out additional nutritional or thyroid issues.

Increased nail fragility during menopause
Linked to hormonal changes and moisture loss
Regular hydration and gentle care can help

For more about menopause and nail changes, visit NIAMS: Menopause and Skin, Hair, and Nail Changes.

35. Nail Fungus (Onychomycosis)

Onychomycosis is the medical term for a fungal infection of the nails, most often affecting the toenails but sometimes fingernails as well. Fungal nail infections cause nails to become thickened, yellow or brown, brittle, and sometimes crumbly or distorted. Risk factors include frequent exposure to damp environments, athlete’s foot, diabetes, weakened immune system, and advancing age. Sharing nail clippers or walking barefoot in communal showers or pool areas also increases risk.
Mild fungal infections can sometimes be managed with over-the-counter antifungal creams or nail lacquers, but these treatments may require consistent use for several months. More advanced cases, or infections that do not respond to topical treatments, often require prescription oral antifungal medications. Persistent or severe infections should be evaluated by a healthcare professional, as untreated onychomycosis can lead to pain, further nail damage, or secondary bacterial infections.

Thickened, discolored, and brittle nails
Over-the-counter treatments for mild cases
Prescription therapy needed for severe or stubborn infections

For more on nail fungus, risk factors, and treatment options, visit the CDC: Nail Fungal Infections.

36. Nail Psoriasis

Nail psoriasis is a manifestation of the autoimmune skin disorder psoriasis, affecting up to half of all people with this condition. Nail changes can include pitting (small dents), discoloration (yellow-brown “oil spots”), thickening, and sometimes separation of the nail from the nail bed (onycholysis). The nails may also become brittle, crumbly, or develop horizontal ridges.
Managing nail psoriasis can be challenging, as nails grow slowly and topical treatments may have limited penetration. Options include prescription topical corticosteroids, vitamin D analogues, or systemic medications for severe cases. Protecting nails from trauma, keeping them trimmed, and avoiding harsh manicures can help prevent further damage. If joint pain accompanies nail changes, psoriatic arthritis should also be considered.

Pitting, discoloration, and thickening of the nails
Oil spots and lifting from the nail bed
Specialized dermatological treatment often required

For a detailed look at nail psoriasis and its management options, visit the National Psoriasis Foundation: Nail Psoriasis.

37. Lichen Planus Nails

Lichen planus is a rare inflammatory condition that can affect the nails, leading to distinctive and sometimes severe changes. Nail lichen planus may cause thinning, longitudinal ridging, splitting, or the appearance of a rough, sandpaper-like texture. In advanced cases, scarring can develop, leading to permanent loss of the nail plate (anonychia) or pterygium formation, where scar tissue extends onto the nail bed. These changes can affect one or several nails and are often accompanied by purple, itchy papules on the skin or mucous membranes.
Because nail lichen planus can progress to irreversible scarring if left untreated, early referral to a dermatologist is essential. Treatment may include topical or injected corticosteroids and other immunosuppressive therapies to reduce inflammation and prevent permanent nail loss.

Longitudinal ridges, thinning, or splitting of nails
Rough, sandpaper-like texture and possible scarring
Urgent dermatology referral for early intervention

For more on lichen planus and nail involvement, visit the DermNet NZ: Nail Lichen Planus.

38. Vitamin Deficiency Signs

Nail changes can often signal underlying vitamin or mineral deficiencies that impact your overall health. For instance, vitamin B12 deficiency may cause darkened nails, brownish streaks, or hyperpigmentation of the nail bed, as well as brittle or spoon-shaped nails. Biotin deficiency can lead to thinning, splitting, and increased susceptibility to fungal infections. Zinc deficiency is often associated with the appearance of white spots or bands and slow nail growth.
Addressing these deficiencies involves a well-balanced diet rich in essential nutrients. Foods high in vitamin B12 include meat, fish, dairy products, and fortified cereals. Biotin is found in eggs, nuts, and whole grains, while zinc sources include seafood, beans, and seeds. If you notice persistent nail changes, consider a nutritional assessment and discuss supplementation with your healthcare provider.

Brownish streaks or darkened nails (B12 deficiency)
Brittle, thin, or splitting nails (biotin deficiency)
White spots or slow growth (zinc deficiency)

For more about nail signs of vitamin deficiencies and dietary advice, visit Harvard T.H. Chan School of Public Health: Vitamin B12.

39. Iron Deficiency Anemia

Iron deficiency anemia commonly manifests in the nails as pallor or the classic spoon-shaped appearance known as koilonychia. Pale nails may be one of the earliest visible signs of low hemoglobin, as the body struggles to deliver enough oxygen to tissues. In more advanced cases, nails become thin, soft, and curve upward at the edges, forming a spoon-like shape. These changes can be accompanied by fatigue, weakness, or shortness of breath.
Diagnosis involves a simple blood test to measure hemoglobin and ferritin levels. If iron deficiency is confirmed, increasing dietary intake of iron-rich foods is essential. Good sources include red meat, poultry, beans, lentils, spinach, and fortified cereals. Vitamin C-rich foods can help enhance iron absorption. In some cases, iron supplements may be recommended by your healthcare provider.

Pale or spoon-shaped nails (koilonychia)
Fatigue and other classic anemia symptoms
Testing and iron-rich diet for management

For more about iron deficiency anemia and nail signs, visit the Mayo Clinic: Anemia.

40. Thyroid Disorder Clues

Thyroid disorders can have a noticeable impact on nail health and appearance. Both hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid) can cause nails to become brittle, dry, and prone to splitting. In hypothyroidism, nail growth slows and the nails may take on a dull, ridged appearance, while hyperthyroidism can sometimes cause onycholysis—where the nail separates from the nail bed.
Nail changes alone are rarely the only sign of thyroid imbalance. Other symptoms may include fatigue, hair loss, weight change, temperature sensitivity, and changes in skin texture. If you experience persistent nail brittleness or slow growth, particularly alongside these symptoms, a thyroid function test (TSH, T3, T4) is warranted. Thyroid disorders are common and manageable, and early diagnosis helps prevent complications.

Brittle, dry, or slow-growing nails
Possible nail separation (onycholysis) in hyperthyroidism
Check thyroid function if symptoms persist

For more on how thyroid health affects your nails, visit American Thyroid Association: Signs and Symptoms.

41. Diabetes-Related Nail Changes

Diabetes can lead to several distinct nail changes, often reflecting broader issues with circulation, immune response, and blood sugar control. Common signs include yellowing of the nails, a result of persistent high blood sugar affecting protein structure, as well as increased risk for fungal infections that cause thickening, discoloration, and splitting. People with diabetes may also notice that their nails grow more slowly and that even minor nail injuries or infections take longer to heal.
Foot care is especially important for those with diabetes, as nerve damage and poor circulation increase the risk of unnoticed injuries and infections. Inspect your feet and nails daily, keep nails trimmed straight across, and moisturize regularly to prevent cracking. Seek prompt medical attention for any signs of infection, redness, or ulcers.

Yellow, thickened, or split nails
Slow nail growth and delayed healing
Daily foot and nail checks are essential

For more tips on diabetic nail and foot care, visit the American Diabetes Association: Foot Complications.

42. Nail Changes in Heart Disease

Heart disease can reveal itself through specific changes in the fingernails, offering early clues to underlying cardiovascular issues. Two of the most notable signs are clubbing—where the fingertips enlarge and the nails curve excessively—and splinter hemorrhages, which appear as thin, red or brown lines under the nail. Clubbing is often associated with chronic low oxygen levels, seen in congenital heart disease or long-standing heart failure, while splinter hemorrhages may be linked to infective endocarditis, a serious infection of the heart’s inner lining.
Because these nail changes are often subtle and develop gradually, they can go unnoticed until more serious symptoms arise. If you observe clubbing or multiple unexplained splinter hemorrhages, especially if accompanied by fatigue, chest pain, or shortness of breath, it is crucial to seek cardiovascular screening. Early detection and management of heart disease can significantly improve outcomes.

Clubbing (rounded, bulbous fingertips)
Splinter hemorrhages (thin, dark streaks under the nail)
Sign of serious heart or vascular conditions

For more on how heart disease can affect your nails, visit Cleveland Clinic: Nail Clubbing.

43. Nail Tumors

Nail tumors are growths that can occur under or around the nail, and they may be either benign (non-cancerous) or malignant (cancerous). Common benign tumors include myxoid cysts, glomus tumors, and warts, all of which can cause visible lumps, nail deformity, or discomfort. Malignant tumors, such as subungual melanoma or squamous cell carcinoma, are far rarer but can be life-threatening if not caught early. Warning signs include a persistent, enlarging growth under or near the nail, changes in color (especially dark streaks), nail destruction, bleeding, or pain that does not resolve.
Early evaluation by a dermatologist or hand specialist is essential for any unexplained mass or persistent change in or around the nail. Diagnosis may involve a biopsy or imaging to determine the nature of the growth. Timely intervention not only improves outcomes for malignant tumors but also helps prevent unnecessary complications from benign growths.

Persistent lumps, bumps, or discoloration under the nail
Non-healing growths or pain
Prompt dermatological evaluation is crucial

For more on nail tumors, warning signs, and when to seek medical care, visit Skin Cancer Foundation: Nail Health.

44. Medication Side Effects

Many medications can influence the appearance and structure of your nails. Chemotherapy drugs are well known for causing a range of nail changes—such as pigmentation, ridges, or even nail loss—due to their effects on rapidly dividing cells. Certain antibiotics, antimalarials, and retinoids can also result in discoloration, thinning, or brittle nails. Some cardiovascular drugs and anticonvulsants may lead to bluish or brownish nail staining, while diuretics and other medications can cause dryness or splitting.
Monitoring your nails for changes while on any new medication is important, especially if you notice sudden discoloration, brittleness, or separation from the nail bed. Most drug-induced changes are reversible once the medication is stopped, but some may linger or require supportive care. Always report new or concerning nail symptoms to your healthcare provider—they can assess whether the changes are benign or if further evaluation is needed.

Pigmentation, brittleness, or nail loss from medications
Monitor for new changes during treatment
Discuss persistent or severe symptoms with your doctor

For a comprehensive overview of how drugs affect nails, visit American Cancer Society: Nail Changes and Chemotherapy.

45. Chronic Disease Monitoring

Nail changes can serve as valuable clues in monitoring chronic illnesses like lupus, rheumatoid arthritis, and other autoimmune diseases. For example, people with lupus may develop red, swollen nail folds (paronychia) or capillary changes visible at the cuticle, while those with rheumatoid arthritis can experience nail pitting, ridging, or increased brittleness. These subtle shifts often reflect underlying inflammation or blood vessel involvement, making nails an important—and sometimes overlooked—window into disease activity.
Regular nail inspections can help patients and healthcare providers catch early warning signs of disease flare-ups or complications. Documenting changes in nail texture, color, or growth can support better disease management and faster intervention if trouble arises. If you live with a chronic illness, make nail checks part of your routine self-care and share new findings at medical appointments.

Red, swollen, or pitted nails in autoimmune diseases
Nails can signal disease activity or complications
Routine checks support proactive care

To learn more about nail changes in lupus and rheumatoid arthritis, visit Lupus Foundation of America: Lupus and Skin.

46. Nail Changes in Children

Children’s nails can display a variety of changes, most of which are benign and resolve with age. Common findings include mild ridging, white spots from minor trauma, or temporary discoloration due to nail biting or thumb sucking. Rapid nail growth and increased susceptibility to minor injuries make these findings frequent in childhood. However, some nail changes in children may signal underlying health concerns.
Rarely, persistent nail abnormalities may be the first sign of genetic conditions such as nail-patella syndrome, ectodermal dysplasia, or congenital malformations. Symptoms like thickened nails, severe pitting, or associated skin and hair changes warrant attention. Chronic nail infections, delayed nail growth, or unexplained color changes should prompt evaluation by a pediatrician or pediatric dermatologist to rule out systemic illness or inherited disorders.

White spots, ridges, or mild discoloration are common and usually harmless
Severe, persistent, or multiple nail abnormalities may indicate genetic or systemic problems
Consult a pediatrician for unusual or lasting changes

For more on pediatric nail changes and when to seek care, see Boston Children’s Hospital: Nail Disorders.

47. Age-Related Nail Changes

Nail changes are a natural part of the aging process. As people grow older, nails may become dull, opaque, brittle, and develop vertical ridges. Growth slows, and nails can thicken, especially toenails, which may become more difficult to trim. Mild yellowing or subtle color changes are also common. These changes are generally harmless and reflect the body’s reduced ability to replenish and hydrate nail cells with age.
It’s important to distinguish normal age-related nail changes from signs of disease. Sudden or severe discoloration, pain, crumbling, or detachment should not be ignored, as they may indicate infection, underlying illness, or medication side effects. Seniors should practice gentle nail care, keep nails clean and trimmed, use moisturizing creams, and wear gloves for household chores to help prevent problems.

Brittleness, vertical ridges, and thickening are normal with age
Watch for sudden or severe nail changes
Moisturizing and gentle care help maintain healthy nails

For more on healthy nail care for seniors, visit National Institute on Aging: Skin and Nail Care.

48. Nail Care Mistakes

Common nail care mistakes can lead to weakened, damaged, or infected nails. Over-trimming—especially cutting nails too short or rounding the corners—can increase the risk of ingrown nails and painful splits. The frequent use of harsh nail products like acetone-based removers, strong detergents, or abrasive files can strip natural oils, leading to dryness, brittleness, and peeling. Aggressive cuticle trimming or picking may also introduce bacteria, causing infections or chronic inflammation.
Safe grooming habits can help maintain healthy nails: trim nails straight across with clean, sharp clippers, file gently in one direction, and avoid harsh chemicals. Moisturize nails and cuticles regularly, and take breaks from nail polish to allow nails to recover. Avoid biting, picking, or scraping at nails, and wear gloves during household cleaning to minimize chemical exposure.

Avoid over-trimming and harsh chemicals
Practice gentle, regular grooming
Moisturize and protect nails from trauma

For expert advice on healthy nail care habits and what to avoid, visit American Academy of Dermatology: Nail Care Tips.

49. Allergic Reactions

Allergic contact dermatitis is a common reaction to chemicals found in nail products, including nail polishes, glues, acrylics, and adhesives. Symptoms may include redness, itching, swelling, blistering, or peeling around the nail folds and fingertips. In more severe cases, the skin may crack or develop a rash that spreads beyond the nails. Repeated exposure to allergens such as formaldehyde, toluene, or acrylates can increase sensitivity over time.
Spotting a reaction early involves watching for sudden or persistent irritation after using a new product. If symptoms occur, discontinue use immediately and wash the area thoroughly. Topical corticosteroids may help relieve mild reactions, but persistent or severe cases should be evaluated by a dermatologist. Hypoallergenic nail polishes and press-on nails made from less irritating materials offer alternatives for sensitive individuals.

Redness, itching, or swelling around nails after product use
Rash or blisters may develop with ongoing exposure
Choose hypoallergenic products or consult a dermatologist if needed

For more on nail product allergies and safe alternatives, visit American Academy of Dermatology: Allergic Contact Dermatitis.

50. When to Seek Professional Help

Knowing when to seek medical advice for nail changes is crucial for early detection and treatment of underlying health problems. Red flags that warrant prompt evaluation include rapid or dramatic changes in nail color or shape, persistent pain, swelling, pus, bleeding, unexplained detachment, or new lumps and growths. Nail changes accompanied by systemic symptoms, such as fever, fatigue, or unexplained weight loss, should also prompt a visit to your healthcare provider.
Before your appointment, make note of all nail changes, the timeline of their development, associated symptoms, and any recent illnesses, medications, or exposures. Bring photos if the changes fluctuate. Trusted resources for preparing and understanding nail health include the American Academy of Dermatology, the Mayo Clinic, and your primary care provider or dermatologist.

Sudden, painful, or persistent nail abnormalities
Nail changes with systemic symptoms
Document symptoms and bring information to your appointment

Timely medical attention can make a significant difference in treating both nail and underlying health conditions.

Conclusion

Your fingernails are much more than a cosmetic detail—they can be an early warning system for your overall health. By paying attention to nail color, shape, and texture, you may detect issues ranging from nutritional deficiencies to chronic diseases at an earlier stage. Proactive self-monitoring—including regular inspection of your nails, maintaining good nail hygiene, and noting any unusual changes—can lead to timely screening and intervention.
If you notice persistent or unexplained nail changes, don’t hesitate to consult a healthcare provider for a thorough evaluation. For further guidance and expert tips, visit trusted sources like the American Academy of Dermatology. Taking these simple steps can help you protect both your nail and overall health.

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