Stroke

What Is a Stroke?

Stroke is a disease that affects the arteries leading to and within the brain. It is the number 5 cause of death and a leading cause of disability in the United States.

A stroke occurs when a blood vessel that carries oxygen and nutrients to the brain is either blocked by a clot or bursts (or ruptures). When that happens, part of the brain cannot get the blood (and oxygen) it needs, so brain cells die.

A stroke, sometimes called a “brain attack,” occurs when blood flow to an area in the brain is cut off. The brain cells, deprived of the oxygen and glucose needed to survive, die. If not caught early, permanent brain damage can result.

How Does a Stroke Occur?

There are two types of stroke.

Ischemic stroke is similar to a heart attack, except it occurs in the blood vessels of the brain. Clots can form either in the brain’s blood vessels, in blood vessels leading to the brain, or even in blood vessels elsewhere in the body that then travel to the brain. These clots block blood flow to the brain’s cells. Ischemic stroke can also occur when too much plaque (fatty deposits and cholesterol) clogs the brain’s blood vessels. About 80% of all strokes are of this nature.

Hemorrhagic stroke occurs when a blood vessel in the brain breaks or ruptures. The result is blood seeping into the brain tissue, causing damage to brain cells. The most common causes of hemorrhagic stroke are high blood pressure and brain aneurysms. An aneurysm is a weakness or thinness in the blood vessel wall.

The brain is an extremely complex organ that controls various body functions. If a stroke occurs and blood flow can’t reach the region that controls a particular body function, that part of the body won’t work as it should.

If the stroke occurs toward the back of the brain, for instance, it’s likely that some disability involving vision will result. The effects of a stroke depend primarily on the location of the obstruction and the extent of brain tissue affected.

Right Brain

The effects of a stroke depend on several factors, including the location of the obstruction and how much brain tissue is affected. However, because one side of the brain controls the opposite side of the body, a stroke affecting one side will result in neurological complications on the side of the body it affects.

For example, if the stroke occurs in the brain’s right side, the left side of the body (and the left side of the face) will be affected, which could produce any or all of the following:

• Paralysis on the left side of the body
• Vision problems
• Quick, inquisitive behavioral style
• Memory loss

Left Brain

If the stroke occurs in the left side of the brain, the right side of the body will be affected, producing some or all of the following:

• Paralysis on the right side of the body
• Speech/language problems
• Slow, cautious behavioral style
• Memory loss 

Think F.A.S.T.

F.A.S.T. is an easy way to remember the sudden signs of stroke. When you can spot the signs, you’ll know that you need to call 9-1-1 for help right away. F.A.S.T. is:

If someone shows any of these symptoms, immediately call 9-1-1 or emergency medical services.

Sudden NUMBNESS or weakness of face, arm, or leg, especially on one side of the body
Sudden CONFUSION, trouble speaking or understanding speech
Sudden TROUBLE SEEING in one or both eyes
Sudden TROUBLE WALKING, dizziness, loss of balance or coordination
Sudden SEVERE HEADACHE with no known cause

What Should I Do If I Experience Stroke-Like Symptoms?

Immediately call 9-1-1. A stroke is a medical emergency. Immediate treatment can save your life or increase your chances of a full recovery from a stroke.

Risk Factors

Up to 50% of all strokes are preventable. Many risk factors can be controlled before they cause problems.

Controllable Stroke Risk Factors

• High blood pressure (High = greater than 140/90 mm/Hg)
• Atrial fibrillation
• Uncontrolled diabetes
• High total cholesterol (200 mg/dL)
• Smoking
• Alcohol (more than one drink per day)
• Being overweight
• Existing carotid and/or coronary artery disease

Uncontrollable Risk Factors

• Age (> 65)
• Gender (men have more strokes, women have deadlier strokes)
• Race (African-Americans are at increased risk)
• Family history

Your doctor can evaluate your risk for stroke and help you control your risk factors. Sometimes, people experience warning signs before a stroke occurs. These are called transient ischemic attacks (also called TIA or mini-stroke) and are short, brief episodes of the stroke symptoms listed above. Some people have no symptoms to warn you prior to a stroke, or the symptoms are so mild they are not noticeable. Regular checkups are important in catching problems before they become serious. Report any symptoms or risk factors to your doctor.