What is the reason for the sudden growth of a bag on the head

The skin of the head suddenly shows a mass, first of all should consider the factors caused by trauma. If the activity accidentally head falls, will cause local performance hematoma performance, so the skin is easy to show a mass. Can be timely to the hospital for local ultrasound examination, first of all can make clear the size of the hematoma, whether there is active bleeding. If the abnormal accumulation of fat tissue in the head, will also form a local mass, this situation is head lipoma. When the mass suddenly increases in a short period of time and shows pain, it should be checked in time to the hospital, combined with the doctor's opinion, and if necessary, consider surgical resection. In addition, trauma causes germs to enter the scalp lymph from the wound skin, causing lymph node swelling to form skin mass.