Stroke FAQs
What is a stroke?
A stroke occurs either when the blood supply to part of the brain is blocked
or when a blood vessel in the brain bursts. Brain cells that do not get oxygen
become injured and die. Death or permanent disability can result. An ischemic stroke
occurs when an artery that supplies blood and oxygen to the brain becomes
blocked, usually by blot clots or by a narrowing of the arteries by a
buildup of plaque (a mixture of fatty substances including cholesterol and
other lipids) and blood clots inside the artery walls. A hemorrhagic
stroke occurs when an artery in the brain bursts. There are two main types
of hemorrhagic stroke. An intracerebral hemorrhage occurs when a blood
vessel in the brain leaks blood into the brain itself. A subarachnoid
hemorrhage is bleeding under the outer membranes of the brain and into the
thin fluid–filled space that surrounds the brain. A subarachnoid hemorrhage
can cause extensive damage to the brain and is the most deadly of all
strokes.
For more information about stroke types, treatment and outcomes, please
see our About Stroke page. What are the
symptoms of stroke?
The National Institute of Neurological Disorders and Stroke notes these
major signs of stroke:
- Sudden numbness or weakness of the face, arms, or legs
- Sudden confusion or trouble speaking or understanding others
- Sudden trouble seeing in one or both eyes
- Sudden trouble walking, dizziness, or loss of balance or coordination
- Sudden severe headache with no known cause
All of the major symptoms of stroke appear suddenly, and often there is
more than one symptom at the same time. What should a bystander do?
If you think someone is having a stroke, you should call 9–1–1 or
emergency medical services right away.
Why is there a need to act fast?
Death or permanent disability can result from a stroke. With timely
treatment, however, the risk of death and disability from stroke can be
lowered. It is very important to know the symptoms of a stroke and act right
away.
What are the risk factors for stroke?
Some conditions as well as some lifestyle factors can put people at a higher
risk for stroke. The most important risk factors for stroke are high blood
pressure, heart disease, diabetes, and cigarette smoking. Persons who have
already had a stroke need to control the risk factors in order to lower
their risk of having another stroke. All persons can take steps to lower
their risk for stroke. For more information about these risk factors, please
see our Risk Factors section. What can
you do to reduce your risk of stroke?
All persons can take steps to lower their risk of stroke by maintaining
normal blood pressure levels or controlling high blood pressure,
preventing or treating heart disease and stroke, and by not using tobacco. What is the burden of stroke on Americans?
Stroke is the third leading cause of death in the United States. About
700,000 strokes occur in the US each year. About 500,000 of these are
first or new strokes. About 200,000 occur in people who have already had a
stroke before. Additionally, stroke is a leading cause of permanent long
term disability. For more stroke facts and statistical information, please
see our Stroke Facts and Statistics
section. What is the cost of stroke for our nation?
According to the American Heart Association, stroke will cost almost $57
billion in direct and indirect costs in 2005 (American Heart
Association. Heart Disease and Stroke Statistics—2005 Update. American
Heart Association; 2004). What is CDC doing to address stroke?
CDC has several programs that address stroke. Most activities are located in
CDC's Division for Heart Disease and Stroke Prevention and are in
collaboration with other federal agencies, state health
departments, and local and tribal organizations. For more
information on these programs, please see our
CDC Addresses Stroke section.
Page last reviewed: October 10, 2007
Page last modified: February 9, 2007
Content source: Division for Heart Disease and Stroke Prevention,
National Center for Chronic Disease Prevention and
Health Promotion
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