What Is It?
A subdural hematoma occurs when a blood vessel near the surface of the brain bursts. Blood builds up between the brain and the brain's tough outer lining. The condition is also called a subdural hemorrhage.
In a subdural hematoma, blood collects immediately beneath the dura mater. The dura mater is the outermost layer of the meninges. The meninges is the three-layer protective covering of the brain.
A subdural hematoma is a life-threatening problem because it can compress the brain.
Most subdural hemorrhages results from trauma to the head. The trauma damages tiny veins within the meninges.
In young, healthy people, bleeding usually is triggered by a significant impact. This type of impact might occur in a high-speed motor vehicle accident.
In contrast, older people may bleed after only a minor trauma. For example, it might happen from falling out of a chair.
A subdural hematoma is also more common in people:
An acute subdural hemorrhage is bleeding that develops shortly after a serious blow to the head. Blood accumulates rapidly, causing pressure to rise within the brain. This can result in loss of consciousness, paralysis or death.
When bleeding develops slowly, it is known as a chronic subdural hemorrhage. Bleeding may develop over a period of weeks to months
This form of bleeding is much more common in older people. The head trauma that causes chronic subdural hemorrhage is often minor. Many of those affected cannot recall a head injury.
Acute subdural hemorrhage usually develops after severe head trauma. Injuries that result in this condition are typically forceful enough to cause a temporary loss of consciousness.
Usually, in the minutes to hours after head injury, the person recovers consciousness. Then, the person gradually loses consciousness again, this time from subdural bleeding.
Other common symptoms of an acute subdural hemorrhage include:
Chronic subdural hemorrhages produce more subtle symptoms. These symptoms may continue for more than a month before the diagnosis is recognized.
These symptoms include:
The symptoms caused by chronic subdural hemorrhage can mimic other common conditions. For example, they may resemble strokes and brain tumors. Occasionally, the gradual memory loss and personality changes can be mistaken for dementia.
All head injuries should be evaluated promptly by a physician. This is especially true if there has been any loss of consciousness.
A doctor usually will want to know:
How the injury occurred
What symptoms developed
Whether there have been head injuries in the past. (Repeat injuries are more likely to cause serious damage.)
Whether the person has other medical problems
What medications the person is taking
Whether the person has been drinking alcohol or using drugs
Whether there are symptoms of other injuries (neck pain, shortness of breath, etc.)
The doctor will perform a thorough physical and neurological exam. He or she will check:
If the doctor suspects bleeding in the head, he or she will order a computed tomography (CT) scan. A CT scan is the best way to determine the location and amount of bleeding. It can also identify any injuries to the brain, skull or neck.
A doctor may suspect a chronic subdural hemorrhage if an older patient develops new neurological symptoms. This is more likely if there has been a fall or minor trauma to the head.
An acute subdural hemorrhage develops over minutes to hours. If not diagnosed and treated promptly, it can cause severe brain injury and sometimes death.
A chronic subdural hemorrhage develops over many days to weeks. The symptoms may be subtle and develop so slowly that the person and family are not alarmed.
As is the case with any brain injury, symptoms can be slow to go away after treatment. Some symptoms may be permanent.
Occasionally, a subdural hematoma is small enough that you may not need surgery to remove the blood. The blood will be reabsorbed gradually by the body. This process may require a few months. But it is sometimes the safest treatment plan.
Accidents, including head injuries, are the leading cause of death in young people. Many of these accidents are related to drugs and alcohol. Many others could be prevented with simple precautions or safety equipment.
To help prevent head injuries:
If you drink alcohol, drink in moderation. Never drive after drinking or using drugs.
If your job involves working high above the ground, use approved safety equipment to prevent accidental falls.
Never work in a high place if you:
Feel lightheaded or unsteady
Have been drinking alcohol
Are taking medication that can make you dizzy or affect your balance
Have your vision checked regularly. Poor vision can increase your risk of falls and other types of accidents.
If you are an older adult, clear your home or apartment of hazards that could cause you to trip and fall. These include throw rugs and extension cords.
If you feel unsteady on your feet, consider using a cane or walker.
If you play a contact sport such as football and you experience a significant head injury, allow adequate time for healing before you start playing again. After a head injury, complete healing can take up to 15 days. This is true even if symptoms go away much sooner. A repeated head injury during this fragile repair period is likely to result in more bleeding. This is called the second impact syndrome.
"Blood-thinning" medications increase your risk of bleeding within the head. Examples include:
An acute subdural hemorrhage requires immediate medical attention. In most cases, emergency surgery must be done to drain the hematoma and to control bleeding.
In contrast, only some chronic subdural hemorrhages require emergency surgery. Most physicians will recommend surgery for larger hemorrhages and those that cause neurological symptoms. However, treatment with bed rest, medications and observation may be reasonable in some cases. This may be the case for smaller hematomas that cause minimal or no symptoms.
People who develop a subdural hemorrhage are at risk of seizures. Seizures may occur even after the hematoma has been treated.
When to Call a Professional
Call for emergency assistance if you find someone unconscious at an accident scene.
Also seek immediate attention if someone with a head injury experiences:
Drowsiness or a decrease in alertness
Nausea or vomiting
Confusion or amnesia
Difficulty walking or poor coordination
Irrational or aggressive behavior
Numbness or paralysis in any part of the body
Even if a head injury appears minor, with mild symptoms, certain people are at high risk of serious bleeding. Call a doctor or go to an emergency room immediately if a person with head injury also:
The outlook for acute subdural hemorrhages generally is poor and some people die even with prompt surgery. Usually there are injuries to other parts of the brain from the trauma. This tends to be true regardless of the size of the hematoma. Many of those who survive may be left with permanent neurological problems.
The prognosis is best in people who:
Don't lose consciousness or are unconscious for a short period of time
Have no or few neurological symptoms when evaluated by a doctor
Are younger than age 50
Do not abuse alcohol
Do not have other associated brain injuries
Receive prompt medical attention
The prognosis for chronic subdural hemorrhage is quite favorable. Most people are able to resume normal functioning.
The prognosis is best in those who, at the time of evaluation:
National Institute of Neurological Disorders and Stroke
P.O. Box 5801
Bethesda, MD 20824
Allergy & Asthma Network Mothers of Asthmatics (AANMA)
2751 Prosperity Ave.
Fairfax, VA 22031
American Association of Neurological Surgeons
5550 Meadowbrook Drive
Rolling Meadows, IL 60008
Brain Injury Association of America
8201 Greensboro Drive
McLean, VA 22102