What is a stroke?

A stroke, also commonly called a brain attack, occurs when a blood vessel in the brain becomes blocked and cells become oxygen deprived and start to die.

There are more than 795,000 strokes occurring in the U.S. each year. According to the Centers for Disease Control and Prevention, a person has a stroke in the U.S. every 40 seconds.

Stroke is one of the top causes of death and/or disability in the United States.

Common related conditions
Ischemic Stroke Hemorrhagic Stroke

Types of strokes

There are two types of strokes:

Ischemic strokes

More than 80 percent of strokes in the U.S. are ischemic strokes that occur when an artery becomes blocked in the brain.

Hemorrhagic strokes

Hemorrhagic strokes occur when you have bleeding in the brain or around the brain.

Causes of strokes

The cause of a stroke depends on what type of stroke it is. If it is an ischemic stroke, it is caused by a blocked blood vessel to the brain. If it is a hemorrhagic stroke, it is caused by bleeding in the brain.

Risk factors for strokes

There are a variety of risk factors that can increase your likelihood of suffering a stroke. These include:

  • High blood pressure (hypertension) — hypertension is the most important stroke risk factor; if you have blood pressure over 120/80, you are at greater risk of suffering from a stroke.
  • Diabetes — people with diabetes are more likely to suffer from a stroke than people who do not have diabetes.
  • Smoking — smoking can interfere with the amount of oxygen that gets to the brain and can increase your likelihood of suffering from a stroke.
  • Age — you are more likely to suffer from a stroke as you age. According to the CDC, more than 75 percent of strokes occur after 65 years of age.
  • Gender — men are more likely to have a stroke at a younger age, but women are more likely to die from a stroke.
  • Race — African Americans, American Indians and Alaska Natives are at greater risk of suffering from a stroke.
  • History of stroke or TIAs (transient ischemic attack) — if you or a family member has had a stroke or mini-stroke (TIA) before, you are more likely to suffer from another stroke.

Symptoms of strokes

The American Heart Association uses the letter’s FAST to raise awareness of the symptoms of a stroke.

  • F — Face dropping
  • A — Arm weakness
  • S — speech problems
  • T — time to call 911

Other symptoms of a stroke include:

  • Confusion
  • Numbness, paralysis or weakness on one side of the body
  • Dizziness
  • Issues with coordination
  • Headache
  • Difficulty seeing

Diagnosis of strokes

If you think you or a family member is having a stroke, call 911 to get to a hospital immediately. Do not drive yourself to the hospital because stroke treatment can begin in the ambulance. Every minute counts during a stroke. Tests that your doctor may order to determine if you are having a stroke include:

  • Physical exam — during an exam, your doctor will take a full medical history, check your blood pressure, listen to your heart and look for broken blood vessels in your eyes.
  • Blood tests — a blood test can determine if your blood is clotting abnormally fast, if your blood sugar is too low or too high or if you have an infection or other blood condition.
  • Imaging tests — a CT or MRI scan can take detailed images of the brain to determine if you have bleeding in the brain or a blockage in a vessel leading to the brain. In some cases, your doctor may inject a dye into the vessels during the test to see blockages more clearly.
  • Carotid ultrasound — a carotid ultrasound can take images inside your neck to see if there is a blockage in the carotid artery.
  • Echocardiogram — an echocardiogram can take detailed images of the heart and determine if there are clots in the heart that may have traveled to the brain.

Treatment of strokes

Treatment for a stroke depends on the type of stroke you are having — either an ischemic stroke or a hemorrhagic stroke.

Ischemic strokes need to be treated quickly to minimize damage to the brain. Treatments for ischemic stroke include:

  • Medications
  • Carotid endarterectomy

Treatments for hemorrhagic strokes include:

  • Medications
  • Aneurysm clipping
  • Coil embolization
  • Arteriovenous malformation (AVM) repair

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