Lump on the Scalp Under the Hair: What to Know

Hair follicles and oil glands can become blocked or inflamed, producing a sore bump or boil. A cyst may feel smooth and round beneath the scalp and may stay unchanged until it becomes irritated. A recent knock can leave swelling or a firm area during healing. Scratching, tight hairstyles, helmets, and hair products may aggravate the skin. Less commonly, a scalp growth can crust, bleed, or enlarge, so a hidden location does not make it safe to ignore. Skin Lumps explains the broader group of causes.

Use a mirror or ask someone you trust to check the surface, noting redness, scale, crust, drainage, and hair loss. Wash gently and avoid picking, squeezing, or trying to drain the area. Reduce pressure from tight headwear and stop a product that clearly irritates the scalp. A clinician can examine the lump and, when needed, recommend observation, medication, sampling, removal, or a steroid injection into the skin for a suitable inflammatory lesion.

Arrange an appointment if the lump persists, enlarges, becomes firm, repeatedly returns, or causes local hair loss. Seek prompt care for warmth, spreading redness, pus, fever, or marked tenderness. A bleeding, ulcerated, or repeatedly crusting scalp lesion should be assessed, particularly when it cannot be seen easily beneath the hair. Sudden severe swelling after a head injury needs urgent evaluation.

Does this feel like a follicle, cyst, or deeper growth? Could a product or hairstyle be irritating it? Should it be photographed, sampled, or removed? What symptoms should prompt an earlier review?