Understanding Stroke Causes and Risk Factors

A stroke happens when blood flow to a part of the brain is suddenly cut off. The brain relies on a constant supply of oxygen-rich blood delivered through arteries that carry blood from the heart. If one of the arteries becomes blocked or bursts, blood can’t reach the brain tissue it normally supplies. Without a steady supply of oxygen-rich blood, brain cells will begin to die. Even a short disruption in blood flow can cause lasting damage in the brain.^2,3

You may hear doctors refer to a stroke with different names, such as a brain attack or a cerebrovascular accident (also known as the medical abbreviation CVA). These terms all mean the same thing.^2,3

Depending on the part of the brain affected, a stroke can affect how you move, speak, or think. Common signs of a stroke include:^2,3

• Face drooping
• Weakness in the arms
• Difficulty speaking

Other stroke symptoms may include sudden weakness or numbness on one side of the body, confusion, trouble seeing, difficulty walking, and severe headache. If you or a loved one experiences these symptoms, it’s important to act quickly. Every minute counts when someone is having a stroke.^2,3

A stroke and a heart attack both happen when blood flow is reduced or blocked.^2-4 The key difference between a stroke and a heart attack is where the blockage occurs. During a stroke, blood flow to the brain is affected.^2,3 During a heart attack, blood flow to the heart muscle is affected.⁴

The signs of a heart attack are also different from those of a stroke and may include:⁵

• Chest pain
• Pain in the arms, neck, back, shoulders, or stomach
• Shortness of breath
• Nausea
• Lightheadedness 

Just like in a stroke, it’s important to seek medical attention right away if you experience any of these symptoms.⁵

A stroke happens when blood flow to part of the brain is interrupted. There are different types of strokes, each with its own cause:^2,3

• Ischemic stroke — When a blood clot blocks an artery supplying blood to the brain^2,3,6
• Hemorrhagic stroke — When a blood vessel in the brain bursts and bleeds into the surrounding tissue^2,3
• Transient ischemic attack (also known as the medical abbreviation TIA) — When blood flow to the brain is temporarily blocked by a clot that dissolves or moves on its own^2,3,7

An ischemic stroke is the most common type of stroke. It accounts for about 87% of all strokes. During an ischemic stroke, a blood clot blocks one of the arteries providing blood to the brain. When the brain artery is blocked, it reduces blood flow (called ischemia).^2,3,6

Blood clots that cause ischemic strokes can form in a blood vessel inside the brain or in another part of the body. When a blood clot forms in the heart and travels through the bloodstream to the brain, it can cause a type of ischemic stroke called a cerebral embolism (also known as an embolic stroke). AFib is the main cause of embolic strokes.^2,3,6

A stroke can affect anyone, but some people have a higher risk than others. Most people who have strokes are older than 55 years. Men are more likely to have a stroke than women. However, when women have a stroke, they’re more likely to die than men.^3,8

AFib is one of the medical conditions that can increase your risk of stroke.⁹ Other health conditions that can also increase your risk of stroke include:^3,8

• Overweight or obesity
• High blood pressure
• High cholesterol
• Diabetes
• Obstructive sleep apnea
• Heart disease, including heart failure and heart defects
• Recent or ongoing COVID-19 infection
• Frequent migraine headaches

There are some stroke risk factors that you can’t control, like your age, sex, and medical conditions.¹⁰ However, your lifestyle habits can also play a big role in your risk of stroke, such as:^3,8

• Not getting enough physical activity
• Drinking alcohol
• Smoking or using other types of tobacco or vaping
• Using recreational drugs

Your doctor can help you understand which risk factors for stroke you may have.

In AFib, the atria (the upper chambers of the heart) beat irregularly. This irregular rhythm prevents the heart from efficiently pumping blood out of the heart with each beat.⁹

The blood left behind in the heart can begin to pool, making it easier for blood cells to stick together and form blood clots. Blood clots often form in a small pouch in the atria called the left atrial appendage (LAA). If a blood clot escapes from the LAA, it can travel to the brain and cause an embolic stroke. ⁹

A medical procedure to close off the LAA can reduce the risk of stroke.¹¹ The WATCHMAN Implant is designed to close off the LAA to prevent blood clots that form here from entering the bloodstream.^12,13

There are risks associated with all medical procedures. Please talk with your doctor about the risks and benefits of the WATCHMAN Implant.

Did you know that 1 out of 3 people with untreated AFib will have a stroke in their lifetime? ¹⁷ Reducing the risk of stroke is one the most important AFib treatments^.14

If your doctor determines that your risk of stroke is high, they may recommend treatments to lower your risk. Blood thinner medications can help prevent the formation of blood clots. But blood thinners can come with side effects and other challenges, like an increased risk of bleeding.¹⁵ Learn more about how blood thinners work.

Some people with non-valvular AFib who need an alternative to blood thinners may be eligible for a permanent solution to close off the LAA, where most stroke-causing blood clots are formed.^11,12 The WATCHMAN Implant is placed in a safe, minimally-invasive one-time procedure to permanently close the LAA. It reduces stroke risk for life – without the need for daily blood thinners.¹³  In a clinical trial, 96% of people were able to stop their blood thinner 45 days after getting the WATCHMAN Implant.¹³