Bruised nail that looks green: what to know

Fresh blood beneath a bruised nail is more often red, purple, brown, or black before it gradually moves outward with nail growth. Green colour can appear when a nail has lifted and moisture becomes trapped underneath, allowing pigment-producing germs to grow. It may occur after artificial nail use, repeated soaking, or damage to the nail seal. Green colour alone does not establish the cause, and a clinician may need to see the nail without polish or an enhancement. More background on changing nail colour is available in [Discoloured Nails](/symptoms/nail-discoloration/).

Remove nail polish so the colour and nail attachment can be observed. Keep the finger clean and thoroughly dry, wear gloves for wet work, and avoid prolonged soaking. Do not seal the area beneath gel, acrylic, or a replacement tip, and do not scrape under the nail or use household chemicals. If an artificial nail is present, avoid pulling it away; arrange careful removal with someone trained to assess the natural nail. A clinician can decide whether treatment or a nail procedure is appropriate; [Nail Surgery](/treatments/surgical-dermatology/nail-surgery/) offers related information.

Arrange an appointment if the green colour remains, spreads, or returns, particularly when the nail is lifting or has an unpleasant smell. Seek prompt care for increasing pain, warmth, swelling, pus, spreading redness, fever, or a cut around the nail. Urgent assessment is appropriate for a cold, pale, blue, numb, badly crushed, or severely painful fingertip. A colour change without a clear injury should also be checked rather than assumed to be a bruise.

Ask whether the colour is consistent with trapped moisture, infection, or old blood, and whether the nail should be trimmed or left intact. Ask how long to keep it dry, whether testing or treatment is needed, and when cosmetic products can be used safely again.