Changes in the appearance of fingernails may be among the earliest warning signs of serious underlying health conditions, with experts urging people not to ignore unusual changes in their nails.
According to US dermatologist Dr Annette Czernik and skin specialist Dr Shamsa Kanwal, nails often provide important clues about a person's overall health before other symptoms appear.
Health experts highlighted five nail abnormalities that may require medical attention.
Clubbed nails may indicate heart or lung disease
If the fingertips become swollen and the nails curve downward over the fingertips, a condition known as clubbing, it may indicate long-term low oxygen levels in the blood.
Doctors say clubbing is commonly associated with serious lung diseases and infections affecting the inner lining of the heart.
Spoon-shaped nails linked to iron deficiency
Nails that become thin and curve inward, resembling a spoon, may be a sign of severe iron deficiency or anaemia.
Experts say low iron levels weaken the tissues that support the nails, causing them to lose their normal shape.
Dark streaks could signal skin cancer
Doctors warn that a sudden black or dark brown line running lengthwise beneath a nail—especially without any history of injury—should never be ignored.
According to dermatologists, such streaks may indicate subungual melanoma, a rare but aggressive form of skin cancer that develops beneath the nail and can spread rapidly if left untreated.
Brittle nails may point to thyroid disorders
Frequent nail breakage, peeling or splitting is often caused by excessive handwashing or exposure to harsh chemicals, but it can also signal an underlying thyroid disorder, experts say.
Thyroid disease can interfere with the body's ability to produce keratin, the protein responsible for healthy nails. Deficiencies in zinc, biotin and vitamin B12 may also contribute to brittle nails.
Discoloured nails may indicate infection or oxygen deficiency
Changes in nail colour can also provide important health clues.
Redness or swelling around the nail may indicate a bacterial infection caused by nail biting or minor injuries.
Bluish nails may suggest low oxygen levels in the blood, while yellow nails can sometimes be linked to liver disease or chronic respiratory conditions.
Health experts recommend that people of all ages undergo regular health check-ups, including cholesterol and blood tests where appropriate, and seek medical advice if they notice persistent or unusual nail changes.
They emphasised that while many nail changes are harmless, some may be early indicators of potentially serious illnesses that benefit from prompt diagnosis and treatment.
