Harvard Health Letters

Like close cousins, heart disease and stroke share a common lineage. Both emerge from a mix of nature (genes), nurture (upbringing and environment), and personal choice (smoking, exercise, etc). For most of us, personal choice largely determines whether a stroke lies ahead. Guidelines on the prevention of stroke suggest that a healthy lifestyle can cut the risk of having one by 80 percent. No drug, device, or other intervention can come close to that!

The term "stroke" conjures up a frightening bolt out of the blue. It certainly feels that way when it happens. But the sudden onset belies a stroke's decades-long development due to slow but steady damage to blood vessels, the growth of artery-clogging plaque, or the development of atrial fibrillation. This long gestation means it's often possible to avoid a stroke by fighting arterial corrosion.

TWO TYPES OF STROKE

A stroke occurs when blood stops flowing to part of the brain. Cut off from their supply of oxygen, brain cells begin dying within minutes. Sometimes the damage is fatal -- stroke is the fourth leading cause of death in the United States, accounting for almost 135,000 deaths each year. Most of the time, stroke isn't a killer.

The American Heart Association estimates that there are more than 6 million stroke survivors in the U.S. Although some have no physical or mental reminders of the attack, many have long-lasting speech loss, paralysis, or other problems. In fact, stroke is a leading cause of disability -- nearly one in three survivors is permanently disabled, and many more need long-term care.

Ischemic strokes occur when a blood clot or other debris blocks a blood vessel in the brain or one leading to it. These account for more than 80 percent of strokes. The rest are hemorrhagic strokes. These occur when a blood vessel in the brain bursts. The bleeding (hemorrhaging) deprives downstream brain cells of oxygenated blood and can also damage cells by increasing pressure inside the brain.

Though ischemic and hemorrhagic strokes require different treatments once they appear, efforts to prevent them are very similar.

Ischemic strokes are more common and occur when a blood clot blocks an artery in the brain. In some cases, the clot develops in the vessel itself (thrombotic stroke). In other cases, the clot forms in the heart or in an artery that carries blood to the brain; the clot breaks off and travels to the brain, where it lodges in a small artery (embolic stroke). Hemorrhagic strokes occur when an artery in the brain ruptures, releasing blood into the brain tissue.

THREE TYPES OF RISK

You can change some, but not all, of the factors that increase your odds of having a stroke.

Nonmodifiable risk factors include your age, gender, genes, birth weight, and race or ethnicity. A 60-year-old African American man who weighed less than 5.5 pounds at birth and whose father had a stroke is far more likely to have a stroke in the next 10 years than a 45-year-old Asian woman who weighed 8 pounds at birth and who has no family history of stroke. Even though you can't change these factors, they set your risk baseline. The higher it is, the more important it is to control the things you can change.

Modifiable risk factors are things that affect stroke risk over which you have some control. These range from high blood pressure and diabetes to smoking and a salty diet.

Many emerging risk factors are under investigation. These include migraine, obstructive sleep apnea (breath holding during sleep followed by explosive snoring), gum disease, blood markers such as lipoprotein(a), and infection.

RISK FACTORS FOR STROKE

-- Factors you can't change:

1. Age

2. Gender

3. Race/ethnicity

-- Factors you can change:

1. High blood pressure

2. Lack of exercise

3. Smoking

4. Diabetes

5. High cholesterol

6. Atrial fibrillation

7. Sickle cell disease

8. Use of oral contraceptives

9. Obesity

10. Presence of other cardiovascular disease

11. Alcohol abuse

12. Drug abuse

Harder to change or emerging evidence:

1. Obstructive sleep apnea

2. Migraine

3. Certain infections

4. Gum disease

5. Blood markers like factor V Leiden, lipoprotein(a), others

STRIKES AGAINST STROKE

You can fight stroke on many fronts. A single thrust is good; a many-pronged attack is even better. Here are 11 things you can do to stay stroke-free:

1. Know and control your blood pressure.

2. Don't smoke; stop if you do.

3. Lose weight if needed.

4. Become more active.

5. Identify and manage atrial fibrillation.

6. Be aggressive about treating a transient ischemic attack (TIA, or mini-stroke).

7. Treat circulatory problems like peripheral artery disease, sickle cell disease, or severe anemia.

8. Know and control your blood sugar and cholesterol.

9. If you drink alcohol, do so in moderation.

10. Adopt a healthy diet low in sodium and rich in potassium.

11. Know the warning signs of stroke and respond immediately.

STROKE WARNING SIGNS

If you notice one or more of the following signs in yourself or someone else, or you're worried that you or someone you're with is having a stroke, call 911 or your local emergency number immediately:

1. Sudden numbness or weakness of the face, arm, or leg, especially on one side of the body

2. Sudden confusion or trouble speaking or understanding

3. Sudden trouble seeing in one or both eyes

4. Sudden problem with walking, loss of balance, or coordination

5. Sudden, severe headache with no known cause.

Starting early is best. Acquiring healthy habits in childhood, the early teens, or young adulthood sets the stage for a healthy adulthood and old age. But if you are tardy in joining the prevention party, it isn't too late. Even small steps now can improve your health. -- Harvard Heart Letter

 

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