A hard bump on the head without pain or itching may be a normal physiological phenomenon, or it may be caused by lipoma, sebaceous cysts and other diseases. 1. Physiological phenomenon: If a hard bag grows on the head for a long time, without pain, itching and other discomforts, it may be a normal physiological phenomenon, generally no need to deal with. 2. Lipoma: It is generally a benign tumor that occurs in soft tissues. It may occur in the soft tissues of the head, if there is no compression of the surrounding blood vessels and nerve tissue, it may be manifested as a painless hard bag on the head. 3. Sebaceous cysts: A hard, painless, itchy bump on the head may also be caused by sebaceous cysts. Sebaceous cysts are formed due to clogged pores. When there is a hard bump on the head that doesn’t hurt or itch, and you can’t tell whether it’s physiological or pathological, it’s recommended that you consult a doctor in time to find out the cause and actively treat it.