A stroke happens when blood flow to a part of your brain is cut off. Without oxygen from the blood, brain cells start dying within minutes. To help prevent a stroke, learn about the causes and the things that can raise your odds of getting one.
Types of Strokes
A stroke can happen in two main ways: Something blocks the flow of blood, or something causes bleeding in the brain.
Ischemic stroke
In 8 out of 10 strokes, a blood vessel that takes blood to your brain gets plugged. It happens when fatty deposits in arteries break off and travel to the brain or when poor blood flow from an irregular heartbeat forms a blood clot.
Hemorrhagic stroke
It is less common than an ischemic stroke but can be more serious. It happens when either a blood vessel in your brain swells and bursts, or when a weakened one leaks. Uncontrolled high blood pressure and taking too much blood thinner medicine can lead to this kind of stroke.
Transient ischemic attack (TIA)
Some people have what's called a TIA. This "mini stroke" is due to a temporary blockage. It doesn't cause permanent brain damage, but it raises your odds of having a full-scale stroke.
What Causes a Stroke?
A stroke happens when something blocks blood from reaching your brain. It could be a blocked blood vessel or bleeding in your brain. You can treat conditions that make you more likely to have a stroke. Other things that put you at risk can't be changed.
How does high blood pressure increase stroke risk?
"High blood pressure is the single biggest driver of stroke," says Kevin Sheth, MD, director of the Yale Center for Brain and Mind Health at the Yale School of Medicine in New Haven, Connecticut. "It damages and weakens blood vessel walls over time, making them more likely to clog or rupture, leading to either ischemic or hemorrhagic stroke." If your blood pressure is typically 130/80 or higher, your doctor will discuss treatments with you.
How does tobacco use cause strokes?
Smoking or chewing tobacco raises your odds of a stroke. Nicotine makes your blood pressure go up. Cigarette smoke causes a fatty buildup in your main neck artery. It also thickens your blood, making it more likely to clot. Even secondhand smoke can affect you.
How is heart disease linked to stroke?
This condition includes defective heart valves as well as atrial fibrillation, or irregular heartbeat, which causes a quarter of all strokes among the very elderly. You can also have clogged arteries from fatty deposits.
How does diabetes raise your chances of having a stroke?
People who have it often have high blood pressure and are more likely to be overweight. Both raise the chances of a stroke. High blood sugar (glucose) caused by diabetes damages your blood vessels, which makes a stroke more likely. If you have a stroke when your blood sugar levels are high, the injury to your brain is greater.
Do weight and physical activity affect stroke risk?
Your chances of a stroke may go up if you're overweight. You can lower your odds by working out every day. Take a brisk, 30-minute walk, or do muscle-strengthening exercises such as pushups and weight training.
Can medications cause a stroke?
Some medicines can raise your chances of stroke. For instance, blood-thinning drugs, which doctors suggest to prevent blood clots, can sometimes make a stroke more likely through bleeding. Studies have linked hormone therapy (used for menopause symptoms such as hot flashes) to a higher risk of strokes. And low-dose estrogen in birth control pills may also make your odds go up.
How does age affect the risk of stroke?
Anyone could have a stroke, even babies in the womb. Generally, your chances go up as you get older. They double every decade after age 55.
Are strokes hereditary?
Strokes can run in families. You and your relatives may share a tendency to get high blood pressure or diabetes. Some strokes can be brought on by a genetic disorder, such as sickle cell disease, or another disorder that blocks blood flow to the brain. If you have a family history of stroke, your own stroke risk increases by an estimated 30%.
How does gender affect stroke risk?
If you're a woman between the ages of 20 and 39, you're two times more likely to have a stroke than men of the same age. Women are also more likely to have strokes later in life, making them less likely to recover and more likely to die as a result.
How are racial and ethnic groups affected differently by stroke?
Strokes affect African Americans, Native Americans, and nonwhite Hispanic Americans much more often than any other group in the U.S. Sickle cell disease, a genetic condition that can narrow arteries and slow down blood flow, is also more common in these groups and in people whose families come from regions such as the Mediterranean, the Middle East, or Asia.
What Are Other Stroke Risk Factors?
Other than the causes listed above, several other things can raise your odds of getting a stroke. These include the following:
High cholesterol (dyslipidemia)
It raises your risk for both ischemic and hemorrhagic strokes, but studies show that use of statins — medications that control the level of LDL (bad) cholesterol — in your blood may lower your risk of stroke.
Diet
A balanced diet high in fruits and vegetables and low in salt lowers your risk for high blood pressure. It also helps you maintain a healthy body weight and glucose levels, lowering your risk for diabetes and stroke.
Alcohol and substance abuse
Studies suggest that drinking even small amounts of alcohol may raise your risk of hemorrhagic stroke. Use of illegal drugs, such as cocaine or heroin, can also raise your risk of ischemic and hemorrhagic strokes.
Infections and inflammation
Inflammation caused by heart disease or other chronic conditions may increase your risk for stroke. Studies suggest that infections such as HIV may slightly raise your risk for stroke. Doctors aren't sure why this is, but they believe HIV may damage the walls of arteries, making them more prone to bursts or clogs.
Takeaways
A stroke is a medical emergency that happens when something blocks the flow of blood to your brain. This can happen when a plug of fat in your arteries breaks off and travels to your brain (ischemic stroke) or when a blood vessel in your brain bursts or leaks (hemorrhagic stroke). Your risk for stroke goes up as you get older, and women are more likely to have strokes than men.
You can't prevent strokes in all cases, but you can lower your risk by maintaining a healthy blood pressure, controlling your blood glucose, eating a balanced diet, and getting regular exercise.
Stroke Causes FAQs
What is the most significant factor for causing strokes?
High blood pressure, also called hypertension, is the single biggest risk factor for strokes. Over time, it damages and weakens your blood vessels, making them more likely to clog or burst.
What type of stroke is caused by stress?
Stress doesn't directly cause stroke, but it can cause dangerous surges in your blood pressure, as well as heart rhythm changes or blood vessel spasms that can increase your risk for both ischemic and hemorrhagic strokes.
Can a stroke cause dementia?
Yes, it can. If your brain goes too long without blood and oxygen, it can cause changes in your behavior, communication, and thinking patterns that are similar to those seen in Alzheimer's. Studies suggest that if you've had a stroke, you may be three times more likely to develop dementia within the next year.
