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Injury to Your Brain

Also called a "brain attack," a stroke is an injury to your brain.

A stroke happens when the blood supply to a part of your brain is interrupted. Insufficient blood supply prevents your brain from receiving the oxygen and nutrients it needs to stay healthy.

Within minutes, your brain tissue begins to die, causing a sudden loss of function. A stroke is a medical emergency and requires quick treatment. With proper treatment, damage to your brain can be minimized, but treatment must begin quickly.

Learn More about Stroke

Comprehensive Stroke Center at BIDMC


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Signs and Symptoms

Symptoms of a stroke start suddenly, and may differ depending on what part of the brain is being affected. Signs and symptoms of a stroke include:

  • Difficulty walking, including sudden dizziness, loss of coordination or loss of balance.
  • Difficulty speaking — speech may be slurred or you may not be able to find the right words to explain what is going on with you, or understand what people are saying to you.
  • Paralysis or numbness on one side of your body, including the face.
  • Difficulty seeing — vision may be blurry, double, dimming or lost.
  • Difficulty swallowing
  • Severe headache, which may come on quickly and may be accompanied by stiff neck, pain between your eyes or vomiting.
  • Confusion
  • Seizures 

Transient Ischemic Attack (TIA)

Also called a "ministroke," a transient ischemic attack or TIA is a warning sign of an impending stroke. A TIA is a temporary reduction in blood flow to a part of your brain. The signs and symptoms of a TIA are the same as for a stroke, but they don't last long — a few minutes up to 24 hours. If the symptoms last longer than 24 hours, it is not a TIA but an actual stroke. You may have more than one TIA. If you have a TIA, see a doctor right away.

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Risk Factors

There are a number of risk factors that can increase your chances of having a stroke, including:

  • High blood pressure
  • Atrial fibrillation (irregular heart rhythm)
  • High cholesterol, particularly high LDL cholesterol
  • Carotid artery disease
  • Aneurysm
  • Coronary artery disease
  • Prior stroke or transient ischemic attack (TIA)
  • Family history of stroke or TIA
  • Arteriovenous malformation (AVM)
  • Smoking
  • Diabetes
  • Obesity
  • Age 55 or older
  • Elevated levels of homocysteine, an amino acid, in your blood
  • Patent foramen ovale (PFO), an abnormal opening of the atrial septum, the thin membrane that separates the left and right sides of the heart's upper chambers or atria

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Causes of Stroke

Ischemic Stroke

Most strokes are of this type. Ischemic stroke happens when the arteries to your brain are blocked or narrowed, reducing blood flow. This causes your brain to be deprived of needed oxygen and nutrients, and brain cells begin to die within a few minutes. There are two main forms of ischemic stroke:

Thrombotic Stroke

  • Occurs when a blood clot forms in an artery that supplies the brain with blood.
  • Blood clots form in arteries that are clogged by fatty deposits called plaques.
  • Thrombotic stroke often involves the carotid arteries in your neck.

Embolic Stroke

  • Occurs when a blood clot forms in a blood vessel away from your brain and is carried through your bloodstream to lodge in smaller brain arteries.
  • Often occurs as a result of an arrhythmia in the heart's upper chambers, known as the atria.
  • Arrhythmia can cause impaired blood flow and formation of a clot.

Hemorrhagic Stroke

Hemorrhagic stroke takes place when a weakened blood vessel in the brain ruptures, causing sudden bleeding in or around the brain. The force of the collecting blood escaping from the vessel can cause excessive pressure in the brain, damaging surrounding brain tissue.

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Diagnosing Stroke

Typically, a stroke is diagnosed in an emergency situation after you have suffered one. Multiple tests, including imaging, may be used to identify whether you are having a stroke and, if so, the cause; or, if you are at risk for stroke.

Learn more about stroke diagnosis at BIDMC »

Neurologic Exam

If you are thought to be having a stroke, a neurologic exam will test you for:

  • awareness and consciousness
  • speech, language and memory function
  • vision and eye movements
  • sensation and movement in the face, arms and legs
  • reflexes 

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Treating Stroke

Treating a stroke quickly is of the utmost importance. The treatment depends on the type of stroke you have suffered.

Medication Treatment for Ischemic Stroke

Treating an ischemic stroke involves quickly restoring blood flow to your brain. The idea is to dissolve the clot or clots that may be blocking blood flow. This can be done by giving medication within three hours of the start of the stroke. Quick treatment improves your chances of survival and reduces the number of complications that may result from your stroke. Medications may include:

  • Tissue Plasminogen Activator (tPA): a powerful clot-busting drug given by IV at the time of an ongoing stroke. It must be given within three hours of the onset of an ischemic stroke. It cannot be used to treat hemorrhagic stroke.
  • Aspirin: likely to be given to you in the emergency room to help prevent you from having another stroke. You should not take aspirin before going to the hospital; if you are having a hemorrhagic stroke, aspirin could make the situation worse.
  • Blood thinners or anti-coagulants: for protection against further embolic events. These include warfarin (Coumadin), Heparin or Lovenox.
  • Antiplatelet agents: for protection against further thrombotic events; these include aspirin, clopidogrel (Plavix) or dipyridamole (Persantine, Aggrenox).
  • Other medications may be given to treat risk factors such as hypertension, high cholesterol, diabetes.

Learn more about procedures used to treat ischemic or hemorhagic stroke »


Complications of stroke may include paralysis or loss of muscle movement; trouble talking or swallowing; memory loss; and pain.

Stroke survivors typically need a lot of help to get over the damage they have suffered. If you have a healthy partner or close friend or relative at home, that is a big help. Even so, rehabilitation can be a long and difficult process. Recovery and rehabilitation depends on the area of the brain that was affected and how much damage was suffered.

Typically, you will be referred to a neurologist who will help plan your rehabilitation program. This may include:

  • Physical therapy to help you regain as much movement as possible
  • Occupational therapy to help you in everyday tasks and self-care
  • Speech therapy to improve swallowing and speech problems

Learn more about recovery after stroke »

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Contact Information

Cardiovascular Medicine
Division of the CardioVascular Institute
Beth Israel Deaconess Medical Center
330 Brookline Avenue
Boston, MA 02215

Act F-A-S-T

How can you tell if you or someone else is having a stroke? Remember to Act F-A-S-T to save brain tissue. Watch for these stroke signs and call 9-1-1 immediately: