Overview
- The American Academy of Dermatology lists warning patterns to watch for—white, half pink/half white, yellow, dusky red half-moons, and dark streaks—and advises seeing a board-certified dermatologist for these changes.
- A new or evolving dark streak under a nail can indicate melanoma, and the NHS urges a GP visit for dark areas not caused by injury.
- White nails may be linked to liver disease or diabetes, with a stronger association in cirrhosis, though age-related whitening can also occur.
- Half pink, half white nails are associated with kidney disease, while dusky red half-moons have been reported with lupus, heart disease, alopecia areata, arthritis, and dermatomyositis.
- Yellow nails may reflect lung disease or lymphatic or circulatory problems but can also result from fungal infection or smoking, and other cues include blue nails (low oxygen), pale nails (anaemia), and blue half-moons (possible poisoning).