AM I AT RISK FOR STROKE?
Treatable Medical Disorders that Increase Stroke Risk Include:
High blood pressure
Having high blood pressure, or hypertension, increases stroke risk four to
six times. It is the single most important controllable stroke risk factor.
High blood pressure is often called "the silent killer" because people can
have it and not realize it, since it often has no symptoms. Hypertension is
a common condition, affecting approximately 50 million Americans, or
one-third of the adult population. Blood pressure is considered
pre-hypertensive if it is consistently more than 120/80. It is classified as
Stage One Hypertnesion if it is over 140/90.
Between 40 and 90 percent of all stroke patients had high blood pressure
before their stroke. Hypertension puts stress on blood vessel walls and can
lead to strokes from blood clots or hemorrhage.
The Seventh Report of the
Joint National Committee on Prevention, Detection, Evaluation, and Treatment
of High Blood Pressure
Heart Disease
Atrial
fibrillation and other heart diseases
Heart disease such as atrial fibrillation
(irregular heartbeat) increases stroke risk up to six times. About 15
percent of all people who have a stroke have something called
atrial fibrillation, or AF, which affects
approximately 2.2 million Americans. AF is caused when the atria (the two
upper chambers of the heart) beat rapidly and unpredictably, producing an
irregular heartbeat. AF raises stroke risk because it allows blood to pool
in the heart. When blood pools, it tends to form clots, which can then be
carried to the brain, causing a stroke.
Normally, all four chambers of the heart beat in the same rhythm, somewhere
between 60 and 100 times every minute. In someone who has AF, the left
atrium may beat as many as 400 times a minute. If left untreated, AF can
increase stroke risk four to six times. Long-term untreated AF can also
weaken the heart, leading to potential heart failure. The prevalence of AF
increases with age. AF is found most often in people over age 65 and in
people who have heart disease or thyroid disorders. Among people age 50 to
59, AF is linked to 6.7 percent of all strokes. By ages 80-89, AF is
responsible for 36.2 percent of all strokes.
Coronary Heart Disease and High Cholesterol
High cholesterol can directly and indirectly increase stroke risk by
clogging blood vessels and putting people at greater risk of coronary heart
disease, another important stroke risk factor. A cholesterol level of more
than 200 is considered "high." Cholesterol is a fatty substance in the blood
that our bodies make on their own, but we also get it from fat in the foods
we eat. Certain foods (such as egg yolks, liver or foods fried in animal fat
or tropical oils) contain cholesterol. High levels of cholesterol in the
blood stream can lead to the buildup of plaque on the inside of arteries,
which can clog arteries and cause heart or brain attack.
Sleep Disordered Breathing - Sleep Apnea
Sleep apnea is a major cardiovascular and stroke risk factor increasing
blood pressure rates, which may cause stroke or heart attack. Studies also
indicate that people with sleep apnea develop dangerously low levels of
oxygen in the blood while carbon dioxide levels rise, possibly causing blood
clots or even strokes to occur. Diagnosing sleep apnea early may be an
important stroke prevention tool.
Personal
history of stroke or TIA
People who have already had a stroke or TIA are
at risk for having another. After suffering a stroke, approximately 5 to 14
percent of survivors will have another stroke within one year. The risk rate
of having another stroke is about 10 percent per year thereafter.
(Sacco et. al.
Survival and Recurrence Following Stroke; The
Framingham Study)
TIA’s are also strong predictors of stroke
because 35 percent of those who experience TIA’s
have a stroke within five years.
Lifestyle
Factors that Increase Stroke Risk Include:
Smoking
Smoking doubles stroke risk. Smoking damages blood vessel walls, speeds up
the clogging of arteries by deposits, raises blood pressure and makes the
heart work harder.
Alcohol
Excessive consumption of alcohol is associated with stroke in a small number
of research studies. Its specific role in stroke has not yet been determined
or proven. Recent studies have also suggested that modest alcohol
consumption (one 4 oz. glass of wine or the alcohol equivalent) may protect
against stroke by raising levels of a naturally occurring "clot-buster" in
the blood.
Weight
Excess weight puts a strain on the entire circulatory system. It also makes
people more likely to have other stroke risk factors such as high
cholesterol, high blood pressure and diabetes.