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Signs and symptoms of an intracranial hematoma may occur from immediately to several weeks or longer after a blow to your head. It's even possible to seem perfectly fine after a head injury. This is called the lucid interval. As time progresses, pressure on your brain increases, producing some or all of the following signs and symptoms:

• Increasing headache
• Vomiting
• Drowsiness and progressive loss of conciousness
• Dizziness
• Confusion
• Pupils of unequal size
• Weakness in limbs on one side of your body
• Increased blood pressure

As more and more blood fills your brain or the narrow space between your brain and skull, other signs and symptoms may become apparent, such as:

• Lethargy
• Seizures
• Unconsciousness

When to see a doctor
An intracranial hematoma can be life-threatening. Emergency medical treatment often is necessary.

Seek immediate medical attention after any significant blow to the head in which:

• You lose consciousness
• You experience any of the signs and symptoms that may indicate an intracranial hematoma

Although symptoms of intracranial hematoma may not be immediately apparent, watch closely for subsequent physical, mental and emotional changes. For example, if someone seemed fine after a blow to the head and was talking to you, but then lapses into unconsciousness, seek immediate medical care.

In addition, tell a family member or a close friend if you've experienced any type of head trauma. Because memory loss often is associated with head trauma, you may forget that you even suffered a blow to the head. An alerted friend, family member or work colleague may be more likely to recognize the warning signs and arrange for prompt medical attention if aware of your history.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

The cause of intracranial bleeding (hemorrhage) is an injury to the head, often as a result of an automobile or motorcycle accident or a seemingly trivial event, such as bumping your head. Mild head trauma is more likely to cause a hematoma if you're an older adult, especially if you're taking an anticoagulant or anti-platelet drugs, such as aspirin. A serious injury may have occurred even if there's no open wound, bruise or other outward sign of damage.

If a hematoma results from the injury to your head, it may occur as a subdural hematoma, an epidural hematoma or an intraparenchymal hematoma.

Subdural hematoma
This occurs when blood vessels — usually veins — rupture between your brain and the outermost of three membrane layers that cover your brain (dura mater). The leaking blood forms a hematoma that compresses the brain tissue. If the hematoma keeps growing, a progressive decline in consciousness occurs, possibly even resulting in death.

There are three types of subdural hematomas:

• Acute. This type is the most serious and potentially life-threatening. It's generally caused by a severe head injury, and signs and symptoms usually appear immediately.
• Subacute. In subacute subdural hematoma, signs and symptoms take longer to appear, sometimes days or weeks after your injury.
• Chronic. Less severe head injuries may cause a chronic subdural hematoma. Bleeding from chronic subdural hematoma may be much slower, and symptoms can potentially take weeks to appear. You may not even recall injuring your head.

All three types require medical attention as soon as signs and symptoms are apparent, or permanent brain damage may result.

The risk of subdural hematoma is greater for people who use aspirin or anticoagulants daily, who abuse alcohol, or who are very old.

Epidural hematoma
Also called an extradural hematoma, this type occurs when a blood vessel — usually an artery — ruptures between the outer surface of the dura mater and the skull. Blood then leaks between the dura mater and the skull to form a mass that compresses the brain tissue.

Some people with this type of injury may remain conscious, but most become drowsy or comatose from the moment of trauma. The risk of dying of an epidural hematoma that affects an artery in your brain is substantial unless you get prompt treatment.

Intraparenchymal hematoma
This type of hematoma, also known as intracerebral hematoma, occurs when blood pools in the brain. After a head trauma, there may be multiple severe intraparenchymal hematomas.

The trauma that causes intraparenchymal hematomas is often responsible for what are called white matter shear injuries. These injuries occur after a trauma literally tears axons in the brain's white matter. Axons are the connections that carry electrical impulses, or messages, from the neurons in the brain to the rest of the body. When this connection is sheared, serious brain damage can result because the neurons can no longer communicate.

Trauma isn't the only cause of intraparenchymal hematoma. Other causes include:

• Blood vessel disorders, such as arteriovenous malformation (AVM) or aneurysm
• Long-term hypertension
• Neurological conditions, such as cerebral amyloid angiopathy
• Brain tumors
• Use of blood thinners
• Certain autoimmune diseases
• Bleeding disorders, such as hemophilia, leukemia and sickle cell anemia
• Central nervous system infection, such as encephalitis
• Drugs, such as cocaine or amphetamines

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Diagnosing an intracranial hematoma can be difficult because individuals may seem fine after an injury. However, doctors generally presume that the progressive loss of consciousness after a head injury is caused by a hemorrhage inside the skull until proved otherwise.

The best method to define the position and size of a hematoma is by an imaging technique. These include:

• Computerized tomography (CT) scan. A CT scan uses a sophisticated X-ray machine linked to a computer to produce detailed images of your brain. You lie still on a movable table that's guided into what looks like an enormous doughnut where the images are taken. CT is the most commonly used imaging scan to diagnose intracranial hematomas.
• Magnetic resonance imaging (MRI) scan. An MRI scan is done using a large magnet and radio waves to make computerized images. During an MRI scan, you lie on a movable table that's guided into a tube, or tunnel. MRIs generally aren't used as often as CT in the diagnoses of intracranial hematomas because the test takes longer to perform and isn't as widely available.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Some subdural hematomas don't need to be removed because they're small and produce no signs or symptoms. Diuretic medications may help control brain swelling (edema) after a head injury.

Surgery
However, hematoma treatment often requires surgery. The type of surgery depends on the characteristics of your hematoma. Options include:

• Surgical drainage. If the blood is localized and isn't clotting excessively, your doctor may create what's called a burr hole through your skull and then remove the liquid by suction.
• Craniotomy. Large hematomas may require that a section of your skull be opened (craniotomy) to remove the blood.

Recovery
After surgery, your doctor may prescribe anticonvulsant drugs, such as phenytoin (Dilantin), to control or prevent post-traumatic seizures. These medications are continued as long as a year after the trauma. Amnesia, attention difficulties, anxiety, sleep problems and headache may occur and continue for some time.

Recovery after an intracranial hematoma can be prolonged and may be incomplete. In adults, most recovery takes place within the first six months after the injury. Children usually recover faster and more completely than adults do.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Patience is the key to coping with brain injuries. Adults will experience the majority of their recovery during the first six months. You may continue to experience smaller, more gradual improvements for up to two years after the hematoma. Children often recover faster and more completely than adults do.

The following tips may help make for a smoother recovery:

• Get adequate sleep at night, and rest in the daytime whenever you feel tired.
• When you're feeling stronger, begin easing back into your normal activities. Don't try to do everything at once.
• Until you get your doctor's OK, don't participate in contact and recreational sports. Avoiding a second injury is crucial.
• After a brain injury, you're reaction times will likely have slowed. Check with your doctor before you begin driving, playing sports, riding a bicycle or operating heavy machinery.
• If you need to take medication, check with your doctor first.
• Don't drink alcohol until you've recovered fully. Alcohol may hinder the recovery process. Excess alcohol consumption can increase your risk of a second injury.
• Write down things that you have trouble recalling.
• Talk with family or close friends before making any important decisions.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

These steps may help to prevent or minimize head injury:

• Use recreational safety equipment. Wear appropriate and properly fitting safety equipment during sports, including a helmet when bicycling, motorcycling, skiing, horseback riding, skating or doing any activity that may result in head injury.
• Buckle your seat belt. Doing so may prevent or minimize damage to your head in a motor vehicle accident.
• Protect your kids. To protect children, use properly fitting car seats, pad countertops and edges of tables, block off stairways, tether heavy furniture or appliances to the wall to prevent tipping, and keep children from climbing on unsafe or unsteady objects.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.