What to Know About a Blood Cyst on the Skin

People may use “blood cyst” for a dark red, purple, or black raised area. It might be a blister containing blood after pinching or friction, a cyst that has become inflamed or injured, a boil, or a growth made from blood vessels. Appearance alone cannot reliably separate these possibilities.

A true epidermoid cyst usually contains keratin rather than blood. Bleeding can occur when a lump is squeezed, rubbed by clothing, shaved over, or otherwise damaged. A clinician may examine its surface, firmness, mobility, opening, and surrounding skin to decide whether treatment or closer investigation is appropriate.

Do not squeeze, puncture, cut, or try to drain the lump yourself. Wash it gently, pat it dry, and cover it with a clean non-stick dressing if the surface has opened. Reduce rubbing from tight clothing or jewellery. If it bleeds, apply steady pressure with clean gauze until it stops.

Note when it appeared and whether its size, colour, tenderness, or drainage changes. A clear photograph can help document change. Treatment depends on the diagnosis: an abscess may need professional drainage, while an intact troublesome cyst may be removed through a planned procedure.

Arrange a dermatology assessment for a new unexplained lump that is enlarging, changing colour or shape, repeatedly crusting or bleeding, failing to heal, or returning after drainage. Prompt care is also sensible when pain, warmth, pus, spreading redness, or fever suggests infection.

Seek urgent help for bleeding that does not stop with sustained firm pressure, rapidly increasing swelling, severe pain, dizziness, or feeling faint. People taking blood-thinning medicine or living with reduced immune protection should mention this when arranging care.

Ask what diagnosis fits the lump, whether infection is present, and whether examination alone is sufficient. You can also ask if observation, an injection, drainage, removal, or laboratory examination of removed tissue would be useful, and how to protect the area while it heals.