If there is no painful symptom and the bag exists for a long time without increasing in size, there is no need for special treatment, it may be a normal tissue of human body called occipital ridge, not a tumor or brain tumor, just continue to observe the changes of the protrusion. If there is local pain, it may be due to the inappropriate pillow that causes the local soft tissue to be repeatedly squeezed, or it may be due to local soft tissue inflammation, such as septic infection, local folliculitis that causes pain. If the lump at the back of the head, within a short period of time in the progressive aggravation, become larger, causing pain symptoms, promptly go to the regular hospital, do not delay the disease.