A painful protrusion on each side of the back of the head is mainly due to local inflammation or swelling of the lymph nodes. Anatomically, these two protrusions are called the mastoid process of the occipital bone, which is the attachment point of the sternocleidomastoid muscle and the cervical-occipital muscle. Prolonged head-down movements will stimulate local inflammation and produce severe pain when pressed with the hand. Sometimes local inflammation causes enlargement of lymph nodes, which is actually an inflammatory reaction of lymph nodes, and it also hurts when pressed. Some people think that this area is a raised bone, but it is not, it is a lymph node, so pay attention to the difference between these two points.