What should you know about a flat hard lump under the skin?

A hard or rubbery lump may arise from a blocked follicle, a boil, a cyst, scar-like tissue, or another skin growth. A boil often becomes tender, warm, and red as inflammation develops. A basal cell carcinoma can instead appear as a persistent pearly or scaly area, a sore that does not heal, or a spot that bleeds easily. These examples describe possible presentations, not a diagnosis from a symptom alone.

A clinician considers how long the lump has been present, whether it moves, and whether the overlying skin has changed.

Do not squeeze, cut, or try to flatten the lump. Photograph it in good light, note its location, and record changes in size, tenderness, colour, or drainage. Arrange an appointment if it persists, grows, recurs, or is difficult to identify. Treatment depends on the cause; an inflamed lesion may sometimes be treated with a steroid injection into the skin, while infection or a suspicious growth requires a different plan.

Seek prompt care for a rapidly enlarging, hot, very painful lump, spreading redness, pus, fever, or red streaks. Have any lump assessed promptly if it repeatedly bleeds, crusts, ulcerates, or fails to heal. Urgent review is also sensible when pain or swelling is affecting movement or sleep.

Ask what features suggest a cyst, boil, or growth, whether the surface needs examination with magnification, and whether a sample or follow-up is needed. Ask which changes should prompt earlier review.