A raised bone at the back of the head is usually called an occipital tuberosity and is a normal physiologic condition. This is a normal physiological phenomenon. It may also be caused by sebaceous cysts, occipital fractures and other diseases. 1. Physiological phenomenon: the back of the head with a protruding bone is a relatively normal physiological structure, everyone will have a protruding bone, but the degree of protrusion of each person is different, is congenitally formed occipital bone protrusion, is located in the middle of the back of the head underneath, will not have an impact on the health of people. 2. Sebaceous cysts: If the cysts are aggravated and inflammation occurs, there will also be an increase in hardness, which is manifested as a cranial bulge. When the cyst is infected, oral antibacterial drugs, such as amoxicillin and cefadroxil, can be given. Surgery can be performed after the inflammation is eliminated. 3. Fracture of occipital bone: it can be accompanied by localized cranial protrusion, which needs to be examined and treated by cranial CT. If intracranial hemorrhage occurs in occipital bone fracture, it is necessary to be hospitalized immediately for systematic treatment, and at the same time, it is necessary to closely observe the change of the condition. If there is a bone protruding from the back of the head, you should go to the hospital surgery to let the doctor check the specific situation, make a clear diagnosis, and then carry out targeted treatment. The above drugs need to be used under the guidance of a doctor, avoid self-medication.