Discovering bumps on the head is common. Many causes are not serious and resolve without specific treatment. This article provides general information about common reasons for head bumps, but it is not a substitute for professional medical advice.
Common Skin-Related Bumps
Hair follicles on the scalp can become inflamed or infected, a condition known as folliculitis. This results in small, red bumps resembling pimples, which can be itchy or tender. Inflammation arises from bacterial or fungal infections, leading to pus-filled lesions around hair shafts.
Cysts are another common type of head bump, sacs filled with fluid, air, or other material. Sebaceous cysts form when a sebaceous gland becomes blocked or damaged, leading to a build-up of sebum, a natural skin oil. These cysts are soft, movable lumps just beneath the skin’s surface, often painless unless infected or ruptured. Epidermal cysts, similar, originate from trapped epidermal cells beneath the skin.
Seborrheic dermatitis, a common skin condition, can manifest on the scalp, causing red, greasy patches covered with flaky white or yellow scales. While known for causing dandruff, severe cases can lead to thickened, irritated areas that feel like raised bumps or plaques. This condition affects areas rich in oil glands, including the scalp, and can cause itching.
Psoriasis is an autoimmune condition that accelerates skin cell growth, leading to thick, silvery scales on red patches. When it affects the scalp, these patches can be raised and feel like bumps, causing itching or discomfort. Rapid skin cell turnover forms these characteristic plaques, which vary in size and distribution.
Less common, benign growths like warts or skin tags can appear on the scalp. Warts are small, rough growths caused by the human papillomavirus (HPV), varying from flat to raised. Skin tags are small, soft, benign growths that appear as a small piece of skin protruding from the surface.
Bumps from Injury or External Factors
Bumps on the head result from direct trauma or injury. A common consequence of a knock or fall is a hematoma, often called a “goose egg.” This occurs when blood vessels beneath the skin rupture, causing blood to collect and form a raised, discolored lump. These bumps are tender and resolve over several days to a few weeks as the body reabsorbs the pooled blood.
Insect bites are another external cause for bumps on the head. Bites from mosquitoes, spiders, or other insects can trigger localized inflammatory reactions, leading to itchy, red, raised welts. The size and duration of these bumps depend on the specific insect, the individual’s sensitivity, and the extent of the reaction.
Allergic reactions can cause bumps on the scalp, particularly through contact dermatitis. This occurs when skin contacts an allergen, such as certain hair dyes, shampoos, or styling products, resulting in an itchy rash, redness, or raised bumps. The reaction appears within hours to a few days after exposure to the irritant or allergen.
When to Seek Medical Attention
While many head bumps are harmless, certain signs indicate medical attention is warranted. Consult a healthcare provider if a bump is accompanied by persistent pain, grows rapidly, or shows signs of bleeding or oozing. Other concerning symptoms include fever, chills, dizziness, confusion, changes in vision, or persistent headache following an injury.
Any bump that appears after a significant head injury, especially if accompanied by loss of consciousness or changes in behavior, requires immediate medical evaluation. If a bump does not resolve on its own within a few weeks, or if it causes ongoing concern, seeking professional medical advice is recommended. This article offers general information and does not replace a consultation with a qualified healthcare provider.