Very large bumps on the scalp may be caused by sebaceous cysts, boils or trauma.
1. Sebaceous cyst: Due to increased sebum secretion from sebaceous glands, the follicular duct opening is blocked and the sebaceous duct dilates, forming a cyst. It manifests as a cystic mass, and can also be red, swollen and painful if the inflammation is severe and infection occurs.
2. Boils: a kind of skin disease caused by bacterial infection, common bacteria include staphylococcus aureus, hemolytic streptococcus, staphylococcus epidermidis, etc., manifested as local redness, swelling, elevated skin temperature, pain, and suppuration.
3. Trauma: head trauma, can cause head soft tissue edema or head hematoma, bulging very big bag, manifested as local pain.
It is recommended to go to the hospital to avoid aggravating the condition of a very large scalp bag.