What is a stroke?

A stroke occurs when a blood vessel in the brain is blocked or bursts. Without blood and the oxygen it carries, part of the brain starts to die. The part of the body controlled by the damaged area of the brain can't work properly.

Brain damage can begin within minutes, so it is important to know the symptoms of stroke and act fast. Quick treatment can help limit damage to the brain and increase the chance of a full recovery.

What are the symptoms?

Symptoms of a stroke happen quickly. A stroke may cause sudden:

• Numbness, weakness, or paralysis of the face, arm, or leg, especially on one side of the body.
• Trouble seeing in one or both eyes. You may have double vision, or things may look dim or blurry.
• Confusion or trouble understanding.
• Slurred or garbled speech.
• Trouble walking. You may feel unsteady, dizzy, or clumsy.
• Severe headache.

If you have any of these symptoms, call 911 or other emergency services right away.

See your doctor if you have symptoms that seem like a stroke, even if they go away quickly. You may have had a transient ischemic attack (TIA), sometimes called a mini-stroke. A TIA is a warning that a stroke may happen soon. Getting early treatment for a TIA can help prevent a stroke.

What causes a stroke?

There are two types of stroke:

• An ischemic stroke develops when a blood clot blocks a blood vessel in the brain. The clot may form in the blood vessel or travel from somewhere else in the blood system. About 8 out of 10 strokes are ischemic (say "iss-KEE-mick") strokes. They are the most common type of stroke in older adults.
• A hemorrhagic stroke develops when an artery in the brain leaks or bursts. This causes bleeding inside the brain or near the surface of the brain. Hemorrhagic (say "heh-muh-RAH-jick") strokes are less common but more deadly than ischemic strokes.

How is a stroke diagnosed?

Seeing a doctor right away is very important. If a stroke is diagnosed quickly-within the first 3 hours of when symptoms start-doctors may be able to use medicines that can lead to a better recovery.

The first thing the doctor needs to find out is what kind of stroke it is: ischemic or hemorrhagic. This is important because the medicine given to treat a stroke caused by a blood clot could be deadly if used for a stroke caused by bleeding in the brain.

To find out what kind of stroke it is, the doctor will do a type of X-ray called a CT scan of the brain, which can show if there is bleeding. The doctor may order other tests to find the location of the clot or bleeding, check for the amount of brain damage, and check for other conditions that can cause symptoms similar to a stroke.

How is it treated?