Sebaceous cysts are small lumps that develop beneath the skin, commonly appearing on the face, neck, scalp, back, and chest. Most grow slowly and are harmless, but some can become irritated, swollen, or uncomfortable over time.

Although commonly called sebaceous cysts, many of these lumps are actually epidermoid cysts. They form when skin cells become trapped beneath the surface and produce keratin, a protein found naturally in the skin, hair, and nails. The material gradually collects inside a small sac, creating a noticeable lump.

Several factors may contribute to cyst formation, including trapped skin cells, damaged hair follicles, and previous skin injuries. Scratches, cuts, or repeated irritation can sometimes push skin cells deeper into the tissue. However, cysts can also develop without an obvious cause.

Most cysts feel soft or firm and may move slightly beneath the skin. Some have a small dark opening in the center. They can remain unchanged for months or years, although inflammation or rupture may cause redness, swelling, warmth, and tenderness.

A warm compress is one simple home-care method that may help soothe discomfort. Apply a clean, warm cloth to the area for 10–15 minutes several times daily. Gently wash the skin with mild soap and water, and avoid unnecessary friction or irritation.

Some people use aloe vera or diluted tea tree oil to soothe irritated skin, but evidence that these remedies treat cysts is limited. Tea tree oil can also cause skin irritation or allergic reactions. Natural remedies generally cannot remove the cyst’s entire sac, so the lump may remain or return.

Never squeeze, puncture, or attempt to pop a cyst at home. Doing so can worsen inflammation, introduce infection, and increase the risk of scarring. Seek medical advice if the lump becomes painful, very red, grows quickly, drains pus or blood, or repeatedly returns.

Many skin cysts require no treatment if they cause no problems. However, a healthcare professional can examine an unfamiliar or changing lump and determine whether treatment is necessary. Depending on its condition, treatment may involve drainage or minor surgery to remove the cyst completely.