Nail Problems
Changes in the color, shape, thickness, or texture of nails
Quick Facts
- Type: Skin and nail symptom
- Common causes: Injury, fungal infection, skin conditions
- Common signs: Discoloration, brittleness, thickening, ridges
- See a doctor: New dark streak, spreading discoloration, pain or swelling
Overview
Nail problems cover a wide range of changes in the fingernails or toenails, including discoloration, thickening, brittleness, ridges, pitting, separation from the nail bed, or changes in shape. Nails grow slowly, so changes often appear gradually and may reflect events or conditions from weeks or months earlier.
Most nail changes are harmless and stem from everyday causes such as minor injury, repeated water exposure, or aging. Some, however, are due to infections, skin conditions like psoriasis, or, less commonly, signs of an internal health problem. Because nails can occasionally reflect what is happening elsewhere in the body, persistent or unexplained changes are worth noting and, when needed, discussing with a clinician.
Because nails grow slowly, it can help to take a clear photo of an affected nail every few weeks to track whether a change is spreading, improving, or staying the same. Noting any recent injury, illness, new products, or occupational exposures also helps a clinician work out the cause more efficiently.
Common Causes
Nail problems have many possible causes:
- Injury: A blow to the nail can cause bruising, dark spots, ridges, or the nail to lift or fall off.
- Fungal infection: A common cause of thick, discolored, crumbly toenails. See onychomycosis.
- Skin conditions: Psoriasis and eczema can cause pitting, ridges, and separation.
- Aging: Nails naturally become more brittle, ridged, or thickened over time.
- Frequent moisture or chemicals: Repeated wetting, detergents, and nail products can weaken nails.
- Nutritional and health factors: Iron deficiency, thyroid disorders, and other conditions can change nail appearance.
- Bacterial infection: Infection around the nail can cause redness, swelling, and pain.
Associated Symptoms
The features that accompany a nail change help identify the cause:
- Discoloration: white, yellow, green, brown, or black
- Thickening, crumbling, or distortion of the nail
- Pitting (small dents) or ridges across or along the nail
- Separation of the nail from the nail bed
- Redness, swelling, pus, or pain around the nail, suggesting infection
- Brittleness, splitting, or peeling
A new dark streak running the length of a nail, or a dark spot that spreads onto the surrounding skin, should be evaluated promptly because, although uncommon, it can be a sign of skin cancer.
Whether one nail or many are involved is a useful distinction. A single affected nail more often results from a localized cause such as injury, infection, or a fungal problem, while changes across many nails at once are more likely to reflect a skin condition or a body-wide health issue. This pattern helps guide the evaluation.
Diagnosis & Evaluation
A clinician can often identify the cause by examining the nails and asking about injuries, occupations, and other symptoms. Evaluation may include:
- A close look at the nails, skin, and surrounding tissue
- Nail clippings or scrapings: Tested in a lab to confirm a fungal or other infection
- Blood tests if a nutritional deficiency, thyroid problem, or other internal cause is suspected
- Biopsy: A small sample of nail or nearby tissue if a serious condition such as skin cancer is being ruled out
Treatment & Management
Treatment depends on the cause:
- Good nail care: Keeping nails clean, dry, and trimmed, moisturizing, and avoiding harsh chemicals and aggressive manicures.
- Antifungal treatment: Topical or oral medicines for fungal nail infections, which can take many months to clear.
- Treating skin conditions: Managing psoriasis or eczema can improve associated nail changes.
- Treating infection: Warm soaks and, when needed, antibiotics or drainage for bacterial infection around the nail.
- Addressing internal causes: Correcting an iron deficiency or thyroid problem may improve nail health.
- Protecting nails: Wearing gloves for wet or chemical work.
When to See a Doctor
See a doctor or dermatologist if you notice:
- A new dark streak in a nail or a dark spot spreading to nearby skin
- Nail changes that come with redness, swelling, pus, or significant pain
- Discoloration or thickening that is spreading or not improving
- Nail changes alongside other symptoms such as fatigue, hair changes, or weight change
- Nail problems in someone with diabetes or a weakened immune system
Prompt care matters most for signs of infection or a new, unexplained dark change in a nail.
Frequently Asked Questions
What causes yellow, thick toenails?
Thick, yellow, crumbly toenails are most often caused by a fungal infection. It is common, especially in older adults, and can take many months to treat with topical or oral antifungal medicine. A clinician can confirm it with a nail sample.
When is a nail change something to worry about?
Most nail changes are harmless. See a doctor for a new dark streak in a nail, a dark spot spreading to nearby skin, signs of infection like redness and pus, or changes that come with other symptoms of illness.
Why are my nails so brittle?
Brittle nails often result from frequent wetting and drying, harsh chemicals, aging, or low iron. Keeping nails moisturized, wearing gloves for wet work, and treating any underlying deficiency can help strengthen them.
Can nail problems be a sign of internal disease?
Sometimes. Iron deficiency, thyroid disorders, and certain other conditions can change the color, shape, or texture of nails. Persistent or unexplained nail changes, especially with other symptoms, are worth discussing with a clinician.
Do white spots on nails mean a calcium deficiency?
Usually not. Small white spots are most often caused by minor injury to the nail as it forms and grow out on their own. They are rarely a sign of calcium or other deficiency.
References
- American Academy of Dermatology Association. Nail health and nail problems.
- Mayo Clinic. Nail fungus and nail care.
- MedlinePlus, U.S. National Library of Medicine. Nail abnormalities.
- National Health Service (NHS). Nail problems.