A stroke occurs when the blood supply to a part of your brain is interrupted or reduced, depriving brain tissue of oxygen and nutrients. Brain cells begin to die in minutes. A stroke is a medical emergency, and prompt treatment is crucial. Early action can minimize brain damage and potential complications.
Strokes are caused by either a blockage of blood flow (ischemic stroke) or a rupture of a blood vessel (hemorrhagic stroke).
Let's explore the causes of ischemic and hemorrhagic strokes in more detail.
What Causes a Stroke
Strokes are caused by disruptions to blood flow in the brain.
- Blocked artery
- Ruptured blood vessel
- High blood pressure
- Atrial fibrillation
- Diabetes
- High cholesterol
- Smoking
- Obesity
- Physical inactivity
- Excessive alcohol consumption
These factors increase the risk of stroke, but not everyone with these risk factors will have a stroke.
Blocked artery
A blocked artery is the most common cause of stroke. When an artery that supplies blood to the brain becomes blocked, it can cause an ischemic stroke.
- Blood clot
A blood clot can form in an artery that is narrowed by plaque, a buildup of fatty material. Plaque can also rupture, causing a blood clot to form at the site of the rupture.
- Narrowed artery
Arteries can become narrowed by atherosclerosis, a condition in which plaque builds up inside the artery walls. Atherosclerosis is the most common cause of stroke.
- Inflammation
Inflammation in the arteries can also lead to stroke. Inflammation can damage the artery walls, making them more likely to form clots.
- Other conditions
Other conditions that can increase the risk of a blocked artery stroke include high blood pressure, diabetes, and atrial fibrillation.
A blocked artery can cause a stroke in any part of the brain. The symptoms of a stroke depend on the part of the brain that is affected.
Ruptured blood vessel
A ruptured blood vessel is another cause of stroke. When a blood vessel in the brain bursts, it can cause a hemorrhagic stroke. Hemorrhagic strokes are less common than ischemic strokes, but they are often more severe.
There are two main types of hemorrhagic strokes:
- Intracerebral hemorrhage
This type of stroke occurs when a blood vessel ruptures within the brain tissue. - Subarachnoid hemorrhage
This type of stroke occurs when a blood vessel ruptures on the surface of the brain.
Ruptured blood vessels can be caused by a number of factors, including:
- High blood pressure
High blood pressure is the leading cause of hemorrhagic stroke. - Aneurysm
An aneurysm is a weak spot in the wall of a blood vessel. Aneurysms can rupture, causing a hemorrhagic stroke. - Trauma
Head injuries can cause blood vessels to rupture. - Blood clotting disorders
People with blood clotting disorders are more likely to have a hemorrhagic stroke. - Brain tumors
Brain tumors can put pressure on blood vessels, causing them to rupture.
The symptoms of a hemorrhagic stroke can vary depending on the size and location of the bleed. Symptoms may include sudden headache, nausea, vomiting, seizures, and loss of consciousness.
High blood pressure
High blood pressure is a major risk factor for both ischemic and hemorrhagic stroke. When blood pressure is high, it puts extra stress on the blood vessels in the brain. This can lead to the formation of blood clots or the rupture of blood vessels.
- Increased risk of atherosclerosis
High blood pressure can damage the arteries, making them more likely to develop atherosclerosis, a condition in which plaque builds up inside the artery walls. Plaque can narrow the arteries and increase the risk of a blood clot.
- Weakened blood vessel walls
High blood pressure can also weaken the walls of blood vessels, making them more likely to rupture.
- Increased risk of aneurysm
High blood pressure can also increase the risk of developing an aneurysm, a weak spot in the wall of a blood vessel. Aneurysms can rupture, causing a hemorrhagic stroke.
- Silent damage
High blood pressure can also damage the brain in ways that are not immediately apparent. For example, high blood pressure can damage the small blood vessels in the brain, which can lead to problems with memory and thinking.
High blood pressure is a serious condition that can lead to a number of health problems, including stroke. It is important to control blood pressure through lifestyle changes, such as eating a healthy diet, exercising regularly, and managing stress. If lifestyle changes are not enough to control blood pressure, medication may be necessary.
Atrial fibrillation
Atrial fibrillation (AFib) is a heart condition that increases the risk of stroke. AFib is a type of irregular heartbeat that can cause blood to pool in the heart, forming clots. These clots can then travel to the brain and block an artery, causing a stroke.
- Increased risk of blood clots
AFib can cause blood to pool in the heart, which can lead to the formation of blood clots. These clots can then travel to the brain and block an artery, causing a stroke.
- Reduced blood flow to the brain
AFib can also reduce blood flow to the brain. This can cause a transient ischemic attack (TIA), which is a temporary interruption of blood flow to the brain. TIAs are often a warning sign that a stroke is imminent.
- Other risk factors
People with AFib are also more likely to have other risk factors for stroke, such as high blood pressure, diabetes, and obesity.
- Silent AFib
Some people with AFib do not experience any symptoms. This is called silent AFib. Silent AFib can still increase the risk of stroke.
AFib is a serious condition that can lead to stroke. If you have AFib, it is important to work with your doctor to manage your condition and reduce your risk of stroke. Treatment for AFib may include medication, lifestyle changes, and surgery.
Diabetes
Diabetes is a chronic disease that affects how the body turns food into energy. There are two main types of diabetes: type 1 and type 2. Both types of diabetes can increase the risk of stroke.
How diabetes increases the risk of stroke:
- High blood pressure
Diabetes can damage the blood vessels, which can lead to high blood pressure. High blood pressure is a major risk factor for stroke.
- High cholesterol
Diabetes can also lead to high cholesterol, another risk factor for stroke.
- Inflammation
Diabetes can also cause inflammation, which is another risk factor for stroke.
- Changes in blood clotting
Diabetes can also affect the way blood clots, which can increase the risk of stroke.
- Silent strokes
People with diabetes are also more likely to have silent strokes, which are strokes that do not cause any noticeable symptoms. Silent strokes can damage the brain and increase the risk of future strokes.
Managing diabetes to reduce the risk of stroke:
- Control blood sugar levels
Keeping blood sugar levels under control is the most important thing people with diabetes can do to reduce their risk of stroke.
- Manage blood pressure and cholesterol
People with diabetes should also work with their doctor to manage their blood pressure and cholesterol levels.
- Make healthy lifestyle changes
Eating a healthy diet, exercising regularly, and maintaining a healthy weight can also help people with diabetes reduce their risk of stroke.
- Take prescribed medications
People with diabetes may also need to take medications to help control their blood sugar levels, blood pressure, and cholesterol.
By managing their diabetes and making healthy lifestyle changes, people with diabetes can reduce their risk of stroke.
High cholesterol
Cholesterol is a waxy substance that is found in all cells of the body. It is essential for many bodily functions, such as producing hormones and building new cells. However, high levels of cholesterol can increase the risk of stroke.
How high cholesterol increases the risk of stroke:
- Atherosclerosis
High cholesterol can lead to the buildup of plaque in the arteries, a condition called atherosclerosis. Plaque is made up of cholesterol, calcium, and other substances. It can narrow the arteries and make them less flexible, which can increase the risk of blood clots. Blood clots can block blood flow to the brain, causing a stroke.
- Inflammation
High cholesterol can also cause inflammation in the arteries. Inflammation can damage the artery walls and make them more likely to rupture. A ruptured artery can cause a hemorrhagic stroke.
- Silent strokes
People with high cholesterol are also more likely to have silent strokes, which are strokes that do not cause any noticeable symptoms. Silent strokes can damage the brain and increase the risk of future strokes.
Managing high cholesterol to reduce the risk of stroke:
- Eat a healthy diet
Eating a healthy diet that is low in saturated fat, cholesterol, and trans fat can help lower cholesterol levels.
- Exercise regularly
Regular exercise can also help lower cholesterol levels.
- Maintain a healthy weight
Maintaining a healthy weight can also help lower cholesterol levels.
- Take prescribed medications
People with high cholesterol may also need to take medications to lower their cholesterol levels.
By managing high cholesterol and making healthy lifestyle changes, people can reduce their risk of stroke.
Smoking
Smoking is one of the most significant risk factors for stroke. Cigarettes contain nicotine, which is a powerful addictive drug. Nicotine can damage the blood vessels and increase the risk of blood clots. Smoking also increases the risk of other conditions that can lead to stroke, such as high blood pressure, high cholesterol, and diabetes.
How smoking increases the risk of stroke:
- Damaged blood vessels
Smoking can damage the blood vessels, making them more likely to develop atherosclerosis, a condition in which plaque builds up inside the artery walls. Plaque can narrow the arteries and increase the risk of blood clots.
- Increased blood pressure
Smoking can also increase blood pressure, another risk factor for stroke.
- Increased risk of blood clots
Smoking can also increase the risk of blood clots. Blood clots can block blood flow to the brain, causing a stroke.
- Increased inflammation
Smoking can also cause inflammation in the body, which is another risk factor for stroke.
- Silent strokes
People who smoke are also more likely to have silent strokes, which are strokes that do not cause any noticeable symptoms. Silent strokes can damage the brain and increase the risk of future strokes.
Quitting smoking to reduce the risk of stroke:
- Quitting smoking is the single most important thing people can do to reduce their risk of stroke.
- The benefits of quitting smoking start immediately and continue to improve over time.
- There are many resources available to help people quit smoking, such as support groups, counseling, and medication.
By quitting smoking, people can significantly reduce their risk of stroke.
Obesity
Obesity is a major risk factor for stroke. People who are obese are more likely to have other risk factors for stroke, such as high blood pressure, high cholesterol, diabetes, and sleep apnea. Obesity can also increase the risk of stroke independently of these other risk factors.
How obesity increases the risk of stroke:
- Increased inflammation
Obesity can cause inflammation in the body, which is a risk factor for stroke.
- Changes in blood clotting
Obesity can also affect the way blood clots, which can increase the risk of stroke.
- Increased risk of diabetes
Obesity is a major risk factor for diabetes, which is another risk factor for stroke.
- Increased risk of heart disease
Obesity is also a major risk factor for heart disease, which is another risk factor for stroke.
- Silent strokes
People who are obese are also more likely to have silent strokes, which are strokes that do not cause any noticeable symptoms. Silent strokes can damage the brain and increase the risk of future strokes.
Managing obesity to reduce the risk of stroke:
- Losing weight
Losing weight can help reduce the risk of stroke, even if you are still overweight or obese.
- Eating a healthy diet
Eating a healthy diet that is low in saturated fat, cholesterol, and trans fat can help lower cholesterol levels and reduce the risk of stroke.
- Exercising regularly
Regular exercise can help lower blood pressure, improve cholesterol levels, and reduce the risk of stroke.
- Managing other health conditions
People who are obese should also work with their doctor to manage other health conditions that can increase the risk of stroke, such as high blood pressure, high cholesterol, and diabetes.
By managing obesity and making healthy lifestyle changes, people can reduce their risk of stroke.