What should you know about a purple lump under the skin?

Colour can come from blood close to the surface, irritation, or inflammation. A tender, warm lump that develops quickly may fit an inflamed spot or [Boils](/conditions/boils/), while a firm or persistent lesion needs a clinician to identify it. A purple lump is a symptom, not a diagnosis, and appearance alone cannot establish cancer. [Basal Cell Carcinoma](/conditions/basal-cell-carcinoma/) more often appears as a changing skin lesion that may bleed or fail to heal, but any unusual growth deserves an individual assessment.

Note when it began, whether it is growing, whether the colour changes, and whether there is pain, warmth, drainage, fever, or nearby swelling. A photograph beside a ruler can help show change without repeatedly pressing it.

Do not squeeze, puncture, massage, or apply strong acids to the lump. Keep the area clean and avoid friction. Arrange a medical review if it remains, enlarges, recurs, or has no clear explanation. A clinician may inspect and feel it, then decide whether monitoring or another test is appropriate. Read more about [Skin Lumps](/symptoms/skin-lumps/) and [Steroid Injection Into The Skin](/treatments/injectables/intralesional-steroid-injection/), which is used only for selected diagnosed lesions.

Seek prompt care for a rapidly enlarging lump, severe pain, spreading redness, pus, fever, red streaking, numbness, or a wound that will not heal. Urgent assessment is also sensible after significant injury if swelling or bruising is extensive, or if the area becomes cold or loses sensation.

Ask what features suggest inflammation, bruising, a cyst, or another growth; whether the lump needs imaging or sampling; and which changes should bring you back sooner.