What should you know about dark lump under skin?

A tender, warm lump that develops quickly can fit an inflamed follicle or boil. A blocked pore or cyst may feel round and mobile, sometimes with a central opening. Bruising or trapped blood can make a lump look dark after pressure or injury. A firm, slowly changing spot may need assessment to distinguish a benign growth from other causes. Basal cell carcinoma can appear as a persistent or changing skin lesion, including one that bleeds or forms a sore, although appearance alone cannot establish the diagnosis.

Do not squeeze, pierce, or repeatedly press the lump, because this can worsen inflammation and complicate examination. Keep the area clean and note its size, colour, tenderness, mobility, and date of onset. Photograph it beside a familiar object for scale. A clinician may examine the surface and deeper tissue and decide whether observation, drainage, sampling, or another treatment is appropriate. Intralesional steroid injection is sometimes used for selected inflammatory lesions, but it is not a general treatment for every dark lump.

Seek urgent care for rapidly spreading redness, severe pain, fever, pus with worsening swelling, or red streaking. Arrange prompt medical review if the lump is growing, firm and fixed, repeatedly bleeding, ulcerated, very dark with irregular borders, or not healing. A lump near the eye, mouth, or airway also warrants timely assessment. Do not wait for pain: some concerning skin lesions can be painless.

Ask what features make the lump more consistent with inflammation, a cyst, a bruise, or a growth. Ask whether it needs imaging, drainage, dermoscopy, or a biopsy, and which changes should prompt you to return sooner.