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

A skin cyst is a sac beneath the surface that may contain keratin. It can feel smooth, rounded, and firm, sometimes moving slightly beneath the fingers. A small opening or thick discharge may be present, but neither feature is required. Inflammation can make the lump red and tender; infection may bring warmth, pus, or feeling unwell. Lipomas, inflamed follicles, abscesses, and other lumps can overlap in appearance. The lump’s exact position, depth, and change over time are more useful than a name guessed at home.

Do not puncture or squeeze the lump. Reduce rubbing, keep the skin clean, and take a clear note of its size and symptoms so you can describe change accurately. A clinician may recommend observation, an anti-inflammatory injection, drainage when an abscess is present, or planned removal for a troublesome cyst. See [Skin Lumps](/symptoms/skin-lumps/) for broader guidance and [Cyst Removal](/treatments/surgical-dermatology/cyst-removal/) for one possible treatment discussion.

Seek prompt care when pain, redness, heat, swelling, pus, or fever develops, or when the lump enlarges quickly. Arrange a clinical examination for a hard or fixed lump, repeated recurrence, bleeding, an ulcer, or uncertainty about whether it is in the skin or deeper tissue. Severe pain with marked swelling or feeling faint needs urgent attention.

What makes this lump more consistent with a cyst than another lesion? Is it confined to the skin? Should I monitor it, treat inflammation, drain it, or consider removal? What symptoms require urgent review?