Brain Basics: Preventing Stroke
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.
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 500,000 Americans have
a stroke, with about 145,000 dying from stroke-related causes.
Officials at the National Institute of Neurological Disorders
and Stroke (NINDS) are committed to reducing that burden through
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: those caused by a blockage of blood flow and those
caused by bleeding. 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 into the brain or the spaces surrounding
the brain causes the second type of stroke, called hemorrhagic
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.
What are Warning Signs of a Stroke?
Warning signs are clues your body sends that your brain is not
receiving enough oxygen. If you observe one or more of these signs
of a stroke or "brain attack," don't wait, call a doctor
or 911 right away!
*Sudden numbness or weakness of face, arm or leg, especially
on one side of the body.
*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
Other danger signs that may occur include double vision, drowsiness,
and nausea or vomiting. Sometimes the warning signs may last only
a few moments and then disappear. These brief episodes, known
as transient ischemic attacks or TIAs, are sometimes called "mini-strokes."
Although brief, they identify an underlying serious condition
that isn't going away without medical help. Unfortunately, since
they clear up, many people ignore them. Don't. Heeding them can
save your life.
What are Risk Factors for a Stroke?
A risk factor is a condition or behavior that occurs more frequently
in those who have, or are at greater risk of getting, a disease
than in those who don't. Having a risk factor for stroke doesn't
mean you'll have a stroke. On the other hand, not having a risk
factor doesn't mean you'll avoid a stroke. But your risk of stroke
grows as the number and severity of risk factors increases.
Stroke occurs in all age groups, in both sexes, and in all races
in every country. It can even occur before birth, when the fetus
is still in the womb. In African-Americans, the death rate from
stroke is almost twice that of the white population. Scientists
have found more and more severe risk factors in some minority
groups and continue to look for patterns of stroke in these groups.
What Are the Treatable Risk Factors?
Some of the most important treatable risk factors for stroke
*High blood pressure. Also called hypertension, this is by far
the most potent risk factor for stroke. If your blood pressure
is high, you and your doctor need to work out an individual strategy
to bring it down to the normal range. Some ways that work: Maintain
proper weight. Avoid drugs known to raise blood pressure. Cut
down on salt. Eat fruits and vegetables to increase potassium
in your diet. Exercise more. Your doctor may prescribe medicines
that help lower blood pressure. Controlling blood pressure will
also help you avoid heart disease, diabetes, and kidney failure.
*Cigarette smoking. Cigarette smoking has been linked to the
buildup of fatty substances in the carotid artery, the main neck
artery supplying blood to the brain. Blockage of this artery is
the leading cause of stroke in Americans. Also, nicotine raises
blood pressure; carbon monoxide reduces the amount of oxygen your
blood can carry to the brain; and cigarette smoke makes your blood
thicker and more likely to clot. Your doctor can recommend programs
and medications that may help you quit smoking. By quitting, at
any age, you also reduce your risk of lung disease, heart disease,
and a number of cancers including lung cancer.
*Heart disease. Common heart disorders such as coronary artery
disease, valve defects, irregular heart beat, and enlargement
of one of the heart's chambers can result in blood clots that
may break loose and block vessels in or leading to the brain.
The most common blood vessel disease, caused by the buildup of
fatty deposits in the arteries, is called atherosclerosis. Your
doctor will treat your heart disease and may also prescribe medication,
such as aspirin, to help prevent the formation of clots. Your
doctor may recommend surgery to clean out a clogged neck artery
if you match a particular risk profile. If you are over 50, NINDS
scientists believe you and your doctor should make a decision
about aspirin therapy. A doctor can evaluate your risk factors
and help you decide if you will benefit from aspirin or other
*Warning signs or history of stroke. If you experience a TIA,
get help at once. Many communities encourage those with stroke's
warning signs to dial 911 for emergency medical assistance. If
you have had a stroke in the past, it's important to reduce your
risk of a second stroke. Your brain helps you recover from a stroke
by drawing on body systems that now do double duty. That means
a second stroke can be twice as bad.
*Diabetes. You may think this disorder affects only the body's
ability to use sugar, or glucose. But it also causes destructive
changes in the blood vessels throughout the body, including the
brain. Also, if blood glucose levels are high at the time of a
stroke, then brain damage is usually more severe and extensive
than when blood glucose is well-controlled. Treating diabetes
can delay the onset of complications that increase the risk of
Do You Know Your Stroke Risk?
Some of the most important risk factors for stroke can be determined
during a physical exam at your doctor's office. If you are over
55 years old, a worksheet in a pamphlet available from the NINDS
can help you estimate your risk of stroke and show the benefit
of risk-factor control.
The worksheet was developed from NINDS-supported work in the
well-known Framingham Study. Working with your doctor, you can
develop a strategy to lower your risk to average or even below
average for your age.
Many risk factors for stroke can be managed, some very successfully.
Although risk is never zero at any age, by starting early and
controlling your risk factors you can lower your risk of death
or disability from stroke. With good control, the risk of stroke
in most age groups can be kept below that for accidental injury
To obtain a copy of the worksheet, write or telephone requesting
the pamphlet Brain Basics: Preventing Stroke from the NINDS Office
of Communications and Public Liaison.
Americans have shown that stroke is preventable and treatable.
A better understanding of the causes of stroke has helped Americans
make lifestyle changes that have cut the stroke death rate nearly
in half in the last two decades.
More than a million stroke survivors suffer little or no long-lasting
disability from their strokes. Another two million, however, live
with the crippling and lifelong disabilities of paralysis, loss
of speech, and poor memory. Scientists at the NINDS predict that,
with continued attention to reducing the risks of stroke and by
using currently available therapies and developing new ones, Americans
should be able to prevent 80 percent of all strokes by the end
of the decade.
National Institute of Neurological Disorders and Stroke
National Institutes of Health
Bethesda, MD 20892