A chronic subdural hematoma is a buildup of blood between the brain and the membrane that covers it, known as the dura. This condition occurs as a result of a head injury and develops slowly over time. The trauma does not have to be serious to produce this condition.
A chronic subdural hematoma begins when a vein ruptures. This causes slow bleeding into the space between the dura and the brain. Over time, the hematoma can enlarge. This puts pressure on the brain and produces mild to severe symptoms.
A chronic subdural hematoma is often caused by a direct blow to the head, such as hitting the head on a rock. It can also occur as a result of an indirect blow, such as when an infant is shaken violently. This causes shaken baby syndrome. During an indirect blow, the brain moves forcefully back and forth, hitting the inside of the skull.
Risk factors for chronic subdural hematoma include: