A subdural hematoma is a collection of blood outside the brain. Subdural hematomas are usually caused by severe head injuries. The bleeding and increased pressure on the brain from a subdural hematoma can be life-threatening. Some subdural hematomas stop and resolve spontaneously; others require surgical drainage.
Symptoms of subdural hematoma depend mostly on the rate of bleeding:
- In head injuries with sudden, severe bleeding causing a subdural hematoma, a person may lose consciousness and become comatose immediately.
- A person may appear normal for days after a head injury, but slowly become confused and then unconscious several days later. This results from a slower rate of bleeding, causing a slowly enlarging subdural hematoma.
- In very slow-growing subdural hematomas, there may be no noticeable symptoms for more than two weeks after the bleeding starts.
Symptoms of subdural hematoma can include:
- Change in behavior
- Nausea and vomiting
- Lethargy or excessive drowsiness