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Stroke Overview

What is a stroke?

According to the Centers for Disease Control and Prevention (CDC), stroke is the fourth-leading cause of death in the United States. Brain tissue loses oxygen when a blood vessel in the brain ruptures and bleeds or if there’s a blockage in the blood supply to the brain. Brain cells and tissue begin to die within minutes, which causes a stroke.

What are the symptoms of stroke?

Stroke symptoms happen in body parts controlled by the brain. Symptoms include:

  • paralysis
  • numbness or weakness in the arm, face, and leg, especially on one side of the body
  • difficulty speaking or understanding speech
  • confusion
  • slurring speech
  • trouble seeing in one or both eyes, with vision blackened or blurred, or double vision
  • trouble walking
  • loss of balance or coordination
  • dizziness
  • severe, sudden headache with an unknown cause

Call 911 if you think someone is having a stroke, as prompt treatment is key to preventing the following outcomes:

  • brain damage
  • long-term disability
  • death

Causes and types of strokes

A stroke caused by a blocked artery is called an ischemic stroke. A stroke caused by a burst or leaking blood vessel is known as a hemorrhagic stroke. Another type of stroke is a transient ischemic attack (TIA), or mini-stroke.

Ischemic stroke

According to the CDC, most strokes are ischemic strokes. In this type of stroke, the arteries supplying blood to the brain narrow or get blocked. These blockages are often caused by blood clots or blood flow that’s severely reduced. The two most common types of ischemic strokes are thrombotic and embolic. A thrombotic stroke happens when a blood clot forms in one of the arteries supplying blood to the brain. An embolic stroke is when a blood clot or other debris forms in another part of the body — often the heart — and moves through the blood and gets stuck in brain arteries, where it causes a blood clot.

Hemorrhagic stroke

A hemorrhagic stroke happens when an artery in the brain suddenly breaks open or leaks blood. That leaking blood creates excess pressure in the skull and swells the brain, damaging brain cells and tissues. This stroke is often caused by high blood pressure and aneurysms. The two types of hemorrhagic strokes are subarachnoid and intracerebral. Intracerebral, the most common type of hemorrhagic stroke, happens when the tissues surrounding the brain fill with blood after an artery bursts. Less common is the subarachnoid hemorrhage, which is bleeding in the area between the brain and tissues that cover it.

Transient ischemic attack (TIA)

A transient ischemic attack, often called a TIA or a mini-stroke, is when blood flow to the brain is blocked for less than five minutes. Symptoms may be temporary and disappear after a few minutes. A TIA is often caused by a blood clot and is a warning of a future stroke. Don’t ignore a TIA. Seek the same treatment you would for a major stroke.

Risk factors for stroke

Certain risk factors make you more susceptible to stroke. According to the National Heart, Lung, and Blood Institute, the more risk factors you have, the more likely you are to have a stroke.


One risk factor is an unhealthy diet. An unhealthy diet that increases your risk of stroke is one that’s high in:

  • salt
  • saturated fats
  • trans fats
  • cholesterol


Inactivity can also raise your risk for stroke. The CDC recommends that adults get 2.5 hours of aerobic exercise every week. That can mean a brisk walk a few times a week.

Alcohol consumption

Your risk for stroke also increases if you drink too much alcohol. According to the Mayo Clinic, alcohol consumption should be in moderation. This means no more than one drink per day for women, and no more than two for men. More than that may raise blood pressure levels and triglyceride levels, which can harden your arteries. Using tobacco also raises your risk, since it can damage your blood vessels and heart. The same goes for smoking, because your blood pressure rises when you use nicotine.

Personal background

There are certain personal risk factors for stroke that you can’t control. Stroke risk can be linked to your:

  • family history
  • sex
  • age
  • race
  • ethnicity

Stroke risk is higher in some families because of genetic health issues, such as high blood pressure. According to the CDC, while both women and men can have strokes, they’re more common in men than in women for most age groups. Age is also a risk factor. The older you are, the more likely you are to have a stroke. Asians and Caucasians are less likely to have a stroke than African-Americans, Hispanics, Alaska Natives, and American Indians.

Certain medical conditions are linked to stroke risk. These include:

  • a previous stroke or TIA
  • high blood pressure
  • high cholesterol
  • heart disorders, such as coronary artery disease
  • heart valve defects
  • enlarged heart chambers and irregular heartbeats
  • sickle cell disease
  • diabetes

Diagnosis of stroke

There are a variety of tests used to aid in stroke diagnosis. These tests can help doctors determine:

  • if you had a stroke
  • what may have caused it
  • what part of the brain is impacted
  • whether you have bleeding in the brain

These tests can also determine if your symptoms are being caused by something else.

You’ll also get a physical exam, during which the doctor will evaluate you for:

  • balance
  • coordination
  • weakness
  • numbness in your arms, face, or legs
  • signs of confusion
  • vision

The doctor will ask you or a family member about your symptoms and what you were doing when they arose. They’ll take your medical history to find out your stroke risk factors. The doctor will also:

  • ask what medications you take
  • check your blood pressure
  • listen to your heart

Tests for stroke

You may go through various tests to further help determine if you’ve had a stroke.

Blood tests

Your doctor might call for blood tests, which can determine:

  • your blood sugar levels
  • if you have an infection
  • your platelet levels
  • how fast your blood clots

MRI and CT scan

You may undergo magnetic resonance imaging (MRI) and a computerized tomography (CT) scan. The MRI will help see if there is any changed brain tissue or damaged brain cells. A CT scan will provide a detailed and clear picture of your brain, which shows any bleeding or damage in the brain. It may also show other brain conditions that may be causing your symptoms.


You may get an electrocardiogram (EKG). This simple test records the electrical activity in the heart, measuring its rhythm and recording how fast it beats. It can help find out if you have any heart conditions that may have led to stroke, such as a prior heart attack.

Cerebral angiogram

Other tests may include a cerebral angiogram. This offers a detailed look at the arteries in your neck and brain.

Carotid ultrasound

You may get a carotid ultrasound, which can show fatty deposits (plaque) and whether your carotid arteries have been narrowed or blocked.


You also may receive an echocardiogram, which can find sources of clots in your heart that may have traveled to your brain and caused a stroke.


You can take measures to prevent stroke by living a healthy lifestyle. This includes the following measures.

Quit smoking

If you smoke, quitting now will lower your risk for stroke.

Consume alcohol in moderation

If you drink excessively, try to reduce your intake. Alcohol consumption can raise your blood pressure.

Keep weight down

Keep your weight at a healthy level. Being obese or overweight increases your stroke risk. To help manage your weight:

  • Eat a diet that’s healthy and full of fruits and vegetables.
  • Eat foods low in cholesterol, trans fats, and saturated fats
  • Stay physically active. This will help you maintain a healthy weight and help reduce your blood pressure and cholesterol levels.

Get checkups

Stay on top of your health. This means getting regular checkups and staying in communication with your doctor. Be sure to take the following steps to manage your health:

  • Get your cholesterol and blood pressure checked.
  • Talk to your doctor about modifying your lifestyle
  • Discuss your medication options with your doctor.
  • Address any heart problems.
  • If you have diabetes, take steps to manage it.

Taking all these measures will help put you in optimal shape to prevent stroke.

Content licensed from:

Written by: the Healthline Editorial Team
Medically reviewed on: Nov 08, 2016: Elaine K. Luo, MD

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
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