Melanonychia symptoms: what should you know?

The most recognisable sign is pigment running from the nail base toward its tip. It may be a narrow line, several lines, or a wider band with shades that range from light brown to black. The nail may otherwise feel normal. Some people notice pigment on more than one nail, while a single-nail change can follow local pressure or injury. Look at the band itself and the skin around the nail rather than relying only on colour.

Photograph the nail beside a ruler or familiar object, using the same lighting each time, and note any pain, tenderness, splitting, bleeding, or recent trauma. Avoid covering the change continuously with opaque polish because this can make comparison difficult. Gentle nail care and roomy footwear reduce further irritation. A clinician can use magnification to assess the stripe and decide whether observation or testing is appropriate.

Book an assessment when the band is new and confined to one nail, becomes wider or darker, develops uneven borders, or spreads onto the surrounding skin. Arrange prompt review for nail lifting, destruction, bleeding, a non-healing sore, or significant pain. These symptoms signal the need for examination; they do not by themselves establish a particular diagnosis.

Ask which symptoms are most relevant in your case, whether the nail should be photographed and reviewed over time, and whether a recent injury or medicine could contribute. Ask how to protect the nail while its cause is being clarified.