What should you know about a painful cyst on the scalp?

A pilar cyst is a sac beneath the scalp that can feel firm and rounded. It may become painful after pressure from brushing, headwear, or lying on it. Pain, redness, warmth, swelling, or pus can indicate inflammation or infection, but pain alone cannot confirm the cause. Other skin lumps can feel similar, so a hands-on examination is useful.

A clinician may ask how quickly the pain began, whether the lump has changed, and whether it has drained. Do not assume that every painful lump is a cyst or that every cyst needs immediate removal.

Leave the lump intact and wash the surrounding scalp gently. Avoid squeezing, piercing, or repeatedly pressing it, because this can worsen irritation and make the skin harder to assess. Keep note of its size, tenderness, redness, and any fluid. A clinician can discuss pain relief that is suitable for you and decide whether observation, treatment of inflammation, or cyst removal is appropriate.

Seek prompt medical advice for spreading redness, increasing warmth, pus, a foul smell, fever, or rapidly worsening pain. Urgent assessment is appropriate if swelling progresses quickly, pain is severe, or you feel faint or very unwell. Arrange a routine review for a lump that persists, recurs, interferes with sleep or hair care, or changes in texture.

Ask whether the lump is consistent with a pilar cyst or another type of skin lump, whether there are signs of infection, and what treatment fits its current state. Ask how to protect it while sleeping or washing your hair and whether removal would reduce repeated episodes.