What should you know about a hard bump on the head under the skin?

On the scalp, a firm spot may be linked to a blocked hair follicle, a small cyst-like swelling, irritation after scratching, or a thicker area of skin. Folliculitis can make bumps sore, red, or centered around a hair. Milia are small, firm, pale cysts near the surface. A single stable bump is assessed differently from several itchy or inflamed spots.

Notice whether the lump is in the skin or feels deeper, whether it moves slightly, and whether there is a scab, discharge, bleeding, or hair loss above it. A photograph and a simple size comparison can help you describe change accurately.

Do not squeeze, pierce, shave over, or repeatedly press the bump. Wash gently, avoid picking, and reduce friction from tight headwear. If it is itchy, ask a pharmacist or clinician whether an antihistamine treatment is suitable for you; medicines can be inappropriate with some conditions or other treatments.

Arrange a dermatology or primary-care assessment if it remains, recurs, or worries you. The clinician may inspect the surface and feel the edges before deciding whether observation or treatment is needed.

Seek prompt medical care if the bump grows quickly, becomes hot and very painful, releases pus, bleeds without clear injury, develops an ulcer, or is accompanied by fever. Seek urgent help after a head injury if there is severe headache, vomiting, confusion, fainting, weakness, or unusual drowsiness.

Ask: Does this appear to arise from a follicle or deeper tissue? What changes should I monitor? Would an examination or removal be appropriate? Could a new shampoo, head covering, or recent injury be contributing?