What should you know about green spots on nails?

A mark under a nail may follow polish, trauma, repeated wet exposure, or separation from the nail bed. Colour that spreads, sits with tenderness, or comes with odour or drainage deserves a clinical review. The spot itself does not identify a condition elsewhere on the body. If you are also dealing with facial or body spots, separate guidance is available for Pimples, Acne, and Folliculitis.

Remove nail polish so the nail can be observed, keep it trimmed without cutting into the skin, and dry carefully after washing. Avoid covering a damp nail with artificial enhancements or scraping underneath it. Do not apply acne or antibiotic products to the nail unless prescribed for that site. Photograph the change in consistent light and note recent injury, manicure, or prolonged water exposure.

Book an assessment if the colour persists, enlarges, or returns after the nail grows, or if the nail becomes loose, painful, thickened, or crumbly. Seek prompt attention for pus, spreading redness, fever, or significant swelling. A clinician may check the nail plate and surrounding skin and decide whether testing or treatment is needed.

Is the nail lifted or infected? Could a product or injury explain the colour? Should I stop manicures, and what changes would mean I need a follow-up visit?