What should you know about solid lump under skin?

A lump may sit within the skin, in fatty tissue beneath it or around a hair follicle. Its texture, mobility, tenderness, colour and speed of change help a clinician narrow the possibilities. A boil can be painful, warm and inflamed, while other lumps may be firm and slow-growing.

A new or changing lump can occasionally be a sign of a skin cancer such as basal cell carcinoma, although a lump alone cannot establish that diagnosis. Examination, dermoscopy or a biopsy may be needed when the appearance is uncertain.

Note when you first noticed the lump, whether it has grown, and whether it bleeds, drains or changes colour. Do not squeeze, puncture or repeatedly massage it; these actions can worsen inflammation and make assessment harder.

Arrange a dermatology review for a new, persistent or changing lump. Bring a list of medicines and mention previous cysts, boils, skin cancers or injections. Treatment may range from observation to drainage, removal or a targeted injection, depending on the diagnosis.

Seek prompt care if the lump is rapidly enlarging, very painful, hot, draining pus, associated with fever or surrounded by spreading redness. Arrange timely assessment for a lump that bleeds, forms a sore that does not heal, becomes fixed or keeps changing.

Ask what features suggest the cause, whether imaging or biopsy is needed, and whether the lump should be watched or treated. Ask how to recognise infection, what procedure is proposed and how a scar may heal.