What Is A Stroke?

What Is Stroke?

Some time around 400 B.C., Hippocrates, often called the father of western medicine, first recognized stroke, which at that time was called apoplexy.

Because doctors knew so little about the brain, for centuries the cause of the condition remained a medical mystery.  Not until 1600 did doctors understand that strokes were “brain attacks” associated with blockages and bleeding in the brain.

A stroke occurs when there is an interruption or blockage of blood supply to the brain tissue. Blood is vital to brain cell health, as it carries oxygen and nutrients to the brain, so without oxygen and nutrients, the brain cells will begin to die.

Stroke can occur either because:

1) A blood vessel in the brain is blocked by a clot or plaque (ischemic stroke)

2) A blood vessel in the brain ruptures (hemorrhagic stroke)

Today, stroke is the fifth leading cause of death and the leading cause of adult disability in the United States. Each year, approximately 800,000 people suffer a stroke, with 2/3 of survivors left with some type of disability. Stroke can happen to anyone at any time, regardless of race, sex or age.

Types Of Stroke

Ischemic stroke is the most common (80%) and occurs when an artery in the brain is blocked, either by a narrowing of the blood vessel (arteriosclerosis) or by a blood clot.

• Thrombotic stroke occurs when a blood clot (thrombus) forms in the artery, usually in areas narrowed by fatty deposits (atherosclerosis)

• Embolic stroke occurs when a clot or other debris (embolus) travels to the brain from somewhere else in the body, and blocks blood flow in an artery. This is often caused by abnormal heart rhythm (heartbeats), such as with atrial fibrillation, that causes pooling of blood in the heart chambers and leads to clot formation

Hemorrhagic stroke occurs when a blood vessel leaks or bursts and causes bleeding in the brain. Hemorrhagic stroke is often associated with high blood pressure but can be due to other causes such as a weakening in the wall of the blood vessel (aneurysm) or a group of abnormally tangled blood vessels (arteriovenous malformation or AVM). Hemorrhagic strokes are less common (20%) but are responsible for more than 30% of all stroke deaths.

• Intracerebral hemorrhage occurs when a blood vessel breaks and bleeds into the surrounding brain tissue. Uncontrolled high blood pressure can damage small arteries in the brain over time, which makes them more likely to rupture

• Subarachnoid hemorrhage occurs when an artery on or near the surface of the brain ruptures (breaks) and bleeds into the space between the brain and the skull. Often this is caused by the bursting of an aneurysm, which can develop with age or be present at birth

Transient Ischemic Attack (TIA) is a “mini stroke” that occurs when a blood clot blocks an artery for a short time. The only difference between a stroke and TIA is that with TIA, the blockage is transient (temporary). Unlike a stroke, when a TIA is over, there is no permanent injury to the brain. However, there is no way to tell if you are having a TIA or major stroke because the signs are exactly the same.

By recognizing TIA symptoms and getting to the hospital, you can get help in identifying why the TIA occurred and get treatment. It is important to seek medical care promptly. Since TIA symptoms dissipate quickly and the body returns to normal, TIAs are often ignored and the problem believed to have passed. Remember do not ignore a TIA. The underlying problem and origin of the TIA continues to be present in your body.

Recognizing Symptoms

The first key to preventing stroke is to know the symptoms.

These include:

  • Sudden confusion, trouble speaking or understanding
  • Sudden trouble seeing in one or both eyes
  • Sudden trouble walking, dizziness, loss of balance or coordination
  • Sudden severe headache with no known cause
  • Sudden numbness or weakness of the face, arm or leg – especially on one side of the body.


If you are in the presence of someone who is exhibiting symptoms of stroke, use the B.U.S.Y.® method to do a layperson’s diagnosis.

B = Body. Ask the person to raise both arms. Does one arm drift downward?

U = Uneven. Ask the person to smile. Does one side of the face droop?

S = Speech. Ask the person to repeat a simple sentence, such as, “Most grass is green.” Does the speech sound slurred or strange?

Y = Yes?. If you observe any of these signs, it’s time to call 9-1-1 — immediately. Every second counts in dealing with Stroke.