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What prevents a second stroke?

Having a stroke is a frightening experience. The good news is that up to 80% of strokes can be prevented with lifestyle changes and medication. However, if you have already had one stroke, your risk of having another is greatly increased. Within 5 years of an initial stroke, the risk of a second stroke ranges from 30-43%. Fortunately, there are many effective ways to prevent a recurrence.

Why is the risk of a second stroke so high?

There are several reasons why having one stroke puts you at increased risk of having another:

  • The initial stroke causes damage to the brain tissue and blood vessels, making that area of the brain more vulnerable to future strokes.
  • Many stroke risk factors like high blood pressure, high cholesterol, and diabetes often persist after the first stroke and continue to damage blood vessels.
  • Blood clots that caused the initial stroke can break off and travel to the brain again, triggering another stroke.
  • Cerebral small vessel disease caused by conditions like high blood pressure can continue to worsen after the first stroke.

The good news is that by properly managing risk factors and making lifestyle changes, studies show the risk of a second stroke can be reduced by up to 80%. Let’s look at the most effective prevention strategies.

Control blood pressure

High blood pressure is the #1 modifiable risk factor for stroke. It damages blood vessels, makes arteries stiffer, and promotes the formation of blood clots. According to the American Stroke Association, keeping blood pressure under 120/80 mm Hg can reduce second stroke risk by up to 30%.

Medications like ACE inhibitors, angiotensin II receptor blockers, calcium channel blockers, and diuretics are commonly used to control high blood pressure after stroke. Lifestyle changes are also important:

  • Following a low sodium diet
  • Getting regular exercise
  • Reducing stress through yoga, meditation, etc.
  • Limiting alcohol intake
  • Quitting smoking

Work closely with your doctor and take medications as directed to keep blood pressure optimized.

Lower cholesterol levels

High LDL (bad) cholesterol levels in the blood promote the buildup of fatty plaque in the arteries. This narrows vessels and makes blood clots more likely to form and cause a stroke. Studies show that lowering LDL cholesterol after stroke can reduce the risk of a recurrence by up to 21%.

Statins are usually prescribed to lower cholesterol. Lifestyle measures include:

  • Eating a diet low in saturated fat
  • Exercising regularly
  • Losing excess weight
  • Consuming foods with soluble fiber like oatmeal and beans

Aim for an LDL cholesterol under 100 mg/dL or lower if directed by your doctor.

Control blood sugar

Diabetes damages blood vessels, making stroke more likely. Even prediabetes increases risk. Getting blood sugar levels under control if you have diabetes or prediabetes can lower stroke recurrence risk by up to 30%.

For diabetes, medications, insulin therapy, diet, exercise, and weight loss are used to optimize blood sugar. If you have prediabetes, lifestyle changes to lose weight and exercise more can often normalize blood sugar levels.

Work toward an A1C level of less than 7% or as close to normal as possible without frequent hypoglycemia.

Take antiplatelet medications

Blood thinners help prevent blood clots from forming and causing strokes. Antiplatelet medications like aspirin, clopidogrel (Plavix), and aspirin/dipyridamole (Aggrenox) are commonly used after stroke. These keep platelets in the blood from sticking together and forming clots.

Studies show antiplatelet therapy can reduce recurrence risk by up to 22%. Taking these medications as directed is key. Let your doctor know if you have any side effects like prolonged bleeding.

Consider anticoagulants

Some strokes are caused by blood clots that form in the heart due to abnormal heart rhythms like atrial fibrillation. Anticoagulant medications like warfarin (Coumadin) help prevent clot formation by thinning the blood.

If you have atrial fibrillation or another condition that increases clotting risk, your doctor may prescribe an anticoagulant after stroke to prevent recurrence. This can lower stroke risk by up to 67%.

Get screened for sleep apnea

Sleep apnea causes pauses in breathing at night and decreases oxygen levels in the blood. This stress on the cardiovascular system increases stroke risk. Studies show treating sleep apnea with CPAP or similar devices can reduce recurrence risk by up to 42%.

If you have symptoms like snoring, daytime fatigue, and insomnia, talk to your doctor about getting a sleep study. Treat any sleep apnea found with CPAP or an oral appliance fitted by a dentist.

Have carotid artery disease evaluated

Carotid artery disease is the narrowing of the major arteries in the neck that supply blood to the brain. It’s caused by plaque buildup and can increase stroke risk. Having significant blockages treated surgically with a carotid endarterectomy can lower recurrence risk by up to 65%.

Your doctor may order an ultrasound scan of the carotid arteries to look for blockages. If any are found, discuss surgery options with a neurologist.

Make lifestyle changes

Leading a healthy lifestyle is key to lowering stroke risk long-term. Important changes include:

  • Quit smoking – Smoking damages blood vessels and thickens the blood. This narrow vessels and promotes clots. Quitting can reduce recurrence risk by up to 42%.
  • Lose weight – Carrying excess body fat leads to higher blood pressure, cholesterol, and blood sugar. Losing just 10 lbs can decrease stroke risk.
  • Exercise more – Regular physical activity helps lower blood pressure, blood sugar, cholesterol, and body weight. Even light exercise helps.
  • Eat a balanced diet – Emphasize vegetables, fruits, whole grains, lean proteins, and healthy fats. Limit sodium, sweets, and refined carbs.
  • Limit alcohol – Drinking more than 1-2 alcoholic beverages per day raises blood pressure. Avoid excess intake.
  • Manage stress – Chronic stress takes a toll on the body and elevates stroke risk factors. Make time to relax.

Take medications reliably

After a stroke, you will likely be prescribed several medications to manage conditions like high blood pressure, diabetes, and high cholesterol to prevent recurrence. But up to 25% of stroke survivors do not take their medications as directed. This puts them at much higher risk of a second stroke.

Reasons people may not take medications reliably include forgetfulness, cost, side effects, and feeling overwhelmed by the regimen. Work with your doctor and pharmacist to come up with solutions. Setting reminders, using pill organizers, getting 90-day supplies, and ordering inexpensive generics can improve compliance.

Never stop a prescribed medication on your own without consulting your doctor. Skipping doses or abruptly stopping medications like blood thinners can be very dangerous.

See your doctor regularly

Ongoing follow-up care with your primary care doctor and neurologist is essential after stroke to prevent recurrence. At least yearly check-ups are recommended, but some patients require visits as frequent as every 1-3 months to monitor health issues.

At these visits, your doctor will check progress on optimizing risk factors like blood pressure, cholesterol levels, and blood sugar. Any new concerning symptoms will also be evaluated. Don’t cancel or skip appointments, even when you feel well.

Recognize warning signs

Being able to identify the signs of a potential second stroke and seeking immediate treatment can prevent lasting damage. Warning signs include:

  • Sudden numbness or weakness of the face, arm or leg, often on one side of the body
  • Confusion, trouble speaking, or difficulty understanding others
  • Vision problems in one or both eyes
  • Trouble walking, dizziness, loss of balance or coordination
  • Severe headache with an unknown cause

At the first sign of a stroke, call 911. Emergency medications can dissolve clots and prevent permanent injury if given in the first 3-4.5 hours after symptoms start.

Consider advanced imaging

Advanced CT and MRI scans like perfusion imaging and intracranial vessel wall imaging can detect subtle blood vessel changes that increase future stroke risk but may not be visible on standard scans. If your doctor suspects these, getting advanced imaging can guide preventative treatment and help avoid a recurrence.

Reduce triglycerides

Having elevated triglycerides, a type of fat in the blood, is linked to higher stroke risk. The American Heart Association recommends a triglyceride level below 150 mg/dL. Triglycerides can be reduced by:

  • Consuming omega-3 fatty acids from fish and plant sources
  • Limiting sugar and refined carbohydrates
  • Exercising regularly
  • Avoiding excess alcohol
  • Taking fibrate medications if levels remain very high

Treat atrial fibrillation

Atrial fibrillation causes the upper chambers of the heart to quiver instead of pumping efficiently. This allows blood clots to form that can travel to the brain and cause a stroke. People with atrial fibrillation have a stroke recurrence risk 4-5 times higher than average.

Treatment options for atrial fibrillation include medications to control heart rate and rhythm, blood thinners, medical procedures like cardioversion or ablation catheter procedures, and devices like pacemakers. Preventing blood clots is key.


A second stroke can be devastating, but up to 80% of recurrences can be prevented through risk factor management and lifestyle changes. By controlling conditions like high blood pressure, diabetes, and atrial fibrillation, taking medications reliably, and leading a healthy lifestyle, your chances of avoiding another stroke can be excellent.

Stay motivated and keep up long-term with all preventative strategies. By working together with your healthcare providers, the possibility of a second stroke can be significantly reduced.