A bump on the back of the head should be normal in most cases. Because the back of the head protrudes a bag of parts, most cases refers to the occipital ridge, also called the occipital ridge, everyone has, but everyone is not necessarily the same size, some people occipital ridge is larger, some smaller. In ancient times, this protruding package would often be used as an anti-bone, which has little scientific basis and is a superstition. In most cases it does not cause significant symptoms and does not require special treatment, continue to observe and avoid repeated local friction. Because repeated friction may cause local sterile inflammation, which may lead to local pain. If the back of the head protrudes a very large bag, it is necessary to actively improve the examination, including cranial CT and MRI, to clarify whether there is a local tumor occupying disease, and if necessary, surgery is required. If the local osteophyte is more serious, it may also cause local protrusion abnormalities, but no special treatment is needed.