An intracranial hematoma occurs when a blood vessel ruptures within your brain or between your skull and your brain. The collection of blood (hematoma) compresses your brain tissue.
An intracranial hematoma may occur because the fluid that surrounds your brain can't absorb the force of a sudden blow or a quick stop. Then your brain may slide forcefully against the inner wall of your skull and become bruised.
Although some head injuries — such as one that causes only a brief lapse of consciousness (concussion) — can be minor, an intracranial hematoma is potentially life-threatening and often requires immediate treatment.
An intracranial hematoma often requires surgery to remove the blood. However, a smaller intracranial hematoma may not require surgery.