A stroke occurs when a blood vessel (artery) that supplies blood to the brain bursts or is blocked by a blood clot. Within minutes, the nerve cells in that area of the brain are damaged, and they may die within a few hours. As a result, the part of the body controlled by the damaged section of the brain cannot function properly.

If you have symptoms of a stroke, you need emergency care, just as though you are having a heart attack. If medical treatment begins soon after symptoms are noticed, fewer brain cells may be permanently damaged.

What causes a stroke?

    * An ischemic stroke is caused by a reduction in blood flow to the brain. This can be caused by a blockage or narrowing in an artery that supplies blood to the brain or when the blood flow is reduced because of a heart or other condition.
    * A hemorrhagic stroke develops when an artery in the brain leaks or bursts and causes bleeding inside the brain tissue or near the surface of the brain.

Before having a stroke, you may have one or more transient ischemic attacks (TIAs), which are a warning signal that a stroke may soon occur. TIAs are often called mini strokes because their symptoms are similar to those of a stroke. However, unlike stroke symptoms, TIA symptoms usually disappear within 10 to 20 minutes, although they may last up to 24 hours.

What are the symptoms?

Symptoms of a stroke begin suddenly and may include:

    * Numbness, weakness, or paralysis of the face, arm, or leg, especially on one side of the body.
    * Vision problems in one or both eyes, such as double vision or loss of vision.
    * Confusion, trouble speaking or understanding.
    * Trouble walking, dizziness, loss of balance or coordination.
    * Severe headache.

How is a stroke diagnosed?

Time is critical in diagnosing and treating a stroke. The first step will be a physical exam and tests of your brain function, followed by a type of X-ray called a CT scan of the brain to establish the type of stroke—ischemic or hemorrhagic. This distinction is critical because the medication given for an ischemic stroke (tissue plasminogen activator, or t-PA) could be life-threatening if given to someone with a hemorrhagic stroke (bleeding in the brain). A prompt diagnosis is also crucial because t-PA should be given within 3 hours of when your symptoms began.

How is it treated?

Ischemic stroke: Doctors will first stabilize your condition and try to restore or improve blood flow to the brain. If less than 3 hours have passed since your symptoms began, tissue plasminogen activator (t-PA), a clot-dissolving medication, may be given. Research shows that the medication can improve recovery from a stroke, especially if given within 90 minutes of your first symptoms. 1

Hemorrhagic stroke: Treatment for a hemorrhagic stroke is difficult. It includes monitoring and controlling bleeding and pressure in the brain and other efforts to stabilize vital signs, especially blood pressure.

After your initial emergency treatment, health professionals will focus on preventing complications such as pneumonia and future strokes. Your health professional will also involve you in a stroke rehabilitation program as soon as possible.

Can I prevent a stroke?

You can help prevent a stroke by eliminating risk factors.

Risk factors that you can change include some diseases. If you can control the disease, you may lower your risk for stroke. Controllable risk factors include:

    * High blood pressure (hypertension). High blood pressure is the second most important stroke risk factor after age.
    * Diabetes. Having diabetes doubles your risk for stroke because of the circulation problems associated with the disease. 2
    * High cholesterol. High cholesterol can lead to coronary artery disease and heart attack, which can damage the heart muscle and increase your risk for stroke.
    * Other heart conditions, such as atrial fibrillation, endocarditis, heart valve conditions, or cardiomyopathy.
    * Smoking. Daily cigarette smoking can increase the risk of stroke 2½ times.