A subdural hematoma is a collection of blood on the surface of the brain.

Subdural hematomas are usually the result of a serious head injury. When they occur in this way, it is called an "acute" subdural hematoma. Acute subdural hematomas are among the deadliest of all head injuries. The bleeding fills the brain area very rapidly, leaving little room for the brain, and are associated with brain injury.

Subdural hematomas can also after a very minor head injury, especially in the elderly. These go unnoticed for many days to many weeks, and are called "chronic" subdural hematomas. During a subdural hematoma, tiny veins between the surface of the brain and its outer covering (the dura) stretch and tear, allowing blood to collect. In the elderly, the veins are often already stretched because of brain atrophy (shrinkage).

Some subdural hematomas occur without cause (spontaneously).

The following increase your risk for a subdural hematoma:

• Head injury
• Very young or very old age
• Anticoagulant medication (blood thinners)
• Long term abuse of alcohol

• Recent head injury
• Loss of consciousness after head injury
• Headache
• Weakness
• Numbness
• Can't speak
• Slurred speech
• Nausea and vomiting
• Lethargy
• Seizures

In infants:

• Bulging fontanelles
• Increased head circumference
• Separated sutures
• Irritability
• High-pitched cry
• Focal seizures
• Generalized tonic-clonic seizure

Always get medical help after a head injury. Older persons should receive medical care if they shows signs of memory problems or mental decline. An exam should include a complete neurologic exam.

Your doctor may order a brain imaging study if you have any of the following symptoms:

• Weakness
• Numbness
• Inability to speak
• Slurred speech
• Persistent headache
• Abnormal level of consciousness
• Recent cognitive decline in an elderly person, even without of head injury

A CT scan or MRI scan would likely be done to evaluate for the presence of a subdural hematoma.