Understanding Stroke Slideshow Pictures Take the Stroke Quiz

Introduction

If you're like most Americans, you plan for your future. When you take a job, you examine its benefit plan. When you buy a home, you consider its location and condition so that your investment is safe. Today, more and more Americans are protecting their most important asset--their health. Are you?

Stroke ranks as the third leading killer in the United States. A stroke can be devastating to individuals and their families, robbing them of their independence. It is the most common cause of adult disability. Each year more than 700,000 Americans have a stroke, with about 160,000 dying from stroke-related causes. Officials at the National Institute of Neurological Disorders and Stroke (NINDS) are committed to reducing that burden through biomedical research.

What is a Stroke?

A stroke, or "brain attack," occurs when blood circulation to the brain fails. Brain cells can die from decreased blood flow and the resulting lack of oxygen. There are two broad categories of stroke:

1. those caused by a blockage of blood flow and
   
   
2. those caused by bleeding.

Blockage of Blood Flow

While not usually fatal, a blockage of a blood vessel in the brain or neck, called an ischemic stroke, is the most frequent cause of stroke and is responsible for about 80 percent of strokes. These blockages stem from three conditions:

• the formation of a clot within a blood vessel of the brain or neck, called thrombosis;
  
  
• the movement of a clot from another part of the body such as the heart to the neck or brain, called embolism; or
  
  
• a severe narrowing of an artery in or leading to the brain, called stenosis.

Bleeding

Bleeding into the brain or the spaces surrounding the brain causes the second type of stroke, called hemorrhagic stroke.

Two key steps you can take will lower your risk of death or disability from stroke: know stroke's warning signs and control stroke's risk factors. Scientific research conducted by the NINDS has identified warning signs and a large number of risk factors.