A heavy layered sheath known as the dura mater covers the outside of the brain and spinal cord. There are blood vessels both under and above the dura.

Bleeding that occurs under the dura is referred to as a subdural hematoma. Subdural hematomas are most common in the elderly, who have fragile veins that can rupture after a minor injury. Surgery is usually required to treat a subdural hematoma.

For more information:

• Subdural hematoma