The cause of the concussion is not entirely clear

Concussion was thought to be a temporary sexual dysfunction of central nervous system, with no visible organic damage, and no gross anatomy or histopathology to indicate a suppression of brain function, it may be related to molecular disorder of brain cell, block of nerve conduction, disturbance of cerebral blood circulation, damage of interneurons and shock wave of cerebrospinal fluid in midline ventricle. Recently, according to the research of nervous system electrophysiology, it is believed that the function of the ascending activation system is the important factor that causes the disturbance of consciousness because of the damage of the Reticular formation. However, these theories can not satisfactorily explain all the phenomena of concussion, such as death due to concussion, chronic brain atrophy and even dementia in professional boxers, and amateur boxers have reported mild impairment of brain function.