What should you know about common cysts on scalp?

A pilar cyst forms from cells associated with a hair follicle and often feels like a rounded, mobile bump. It may be noticed while washing or brushing the hair. A cyst can remain unchanged, but friction from combing, hats, or picking may make it sore. Redness, warmth, swelling, or drainage can signal inflammation or infection; a clinician may need to distinguish it from another type of skin lump.

Do not squeeze, puncture, or cut the lump at home, since this can injure the scalp and push material deeper. Keep the area clean, avoid repeated rubbing, and note whether its size, tenderness, or surface changes. A clinician can examine it and discuss observation or [Cyst Removal](/treatments/surgical-dermatology/cyst-removal/) when it repeatedly catches on clothing, becomes inflamed, or interferes with daily care. Other unexplained [Skin Lumps](/symptoms/skin-lumps/) may need a different approach.

Arrange an assessment for a new, enlarging, painful, red, warm, bleeding, or draining scalp lump. Seek prompt medical care if swelling spreads, fever develops, or pain becomes marked. A rapidly changing lesion should be examined rather than assumed to be a cyst.

Could this be a pilar cyst or another scalp lump? What changes should I monitor? If removal is appropriate, will the cyst and its capsule be addressed, and how should I care for the scalp afterward?