Aspirin for Stroke


Aspirin, also known by its chemical name, acetylsalicylic acid, is a medicine that has been around for generations and is one of the most well understood medications. It is often recommended for the prevention of blood clots, which can cause strokes or heart attacks.

Aspirin for Stroke Prevention

Strokes are often caused by blood clots, which can form in a blood vessel located either inside the brain or elsewhere in the body (usually in the heart) and travel to the brain, blocking a blood vessel in the brain..

Aspirin can help prevent the formation and enlargement of blood clots that can cause strokes. Studies have shown that the use of daily aspirin has been found to help prevent the occurrence of stroke in people who are at risk. A study published in the journal, Neurotherapeutics evaluated a number of research experiments that were done on aspirin. The article reports that the use of daily aspirin demonstrates a significant reduction in stroke. Another research article published in the International Journal of Women’s Health specifically evaluated the effects of taking daily aspirin on women who were at risk of stroke and reported that aspirin is associated with a considerable decline of stroke incidence in women.

The benefits of daily aspirin therapy have only been established for people who have risk factors for stroke, and thus there is no reason for someone without stroke risk factors to start taking aspirin for the prevention of stroke.

Despite the fact that aspirin is an over the counter medicine that does not require a prescription, the use of aspirin for stroke prevention should be started only if your doctor recommends it.

How Does Aspirin Work?

Aspirin works to prevent blood clot formation by interfering with the function of small cells called platelets that function by clustering together to form a blood clot that prevents bleeding.

When platelets form a clot that blocks a blood vessel in the brain, a stroke may result. Aspirin interferes with the development and enlargement of platelet clumps by preventing a substance called thromboxane from holding the platelets together.

Side Effects

Aspirin can produce a number of side effects. Some of the side effects are a direct result of its anti-platelet action. Bleeding anywhere in the body due to the reduction in the formation of blood clots can result. Bleeding can cause inadequate wound healing, excessive bruising, bleeding in the brain, (hemorrhagic stroke) and bleeding from the bladder (in the urine) or within the digestive system. Aspirin can also induce bleeding of the digestive system due to irritation of the stomach lining. Coated aspirin may help reduce stomach irritation. Symptoms of digestive bleeding include stomachaches, pain and dark tarry appearing stools (poop.)  

Unusual Side Effects

Aspirin can produce side effects unrelated to bleeding, such as ringing in ears, dizziness or seizures.

An unusual side effect called Reye’s syndrome may affect predisposed children if they use aspirin, so it is not generally recommended for children.

When to Avoid Aspirin

If you suffer from bleeding disorders, kidney disease or liver disease, the use of aspirin may cause more serious side effects. Some people are allergic to aspirin or are unable to tolerate any medication that contains salicylic acid, and thus should not take aspirin for any reason.

Aspirin may interact with some medications, particularly with other blood thinners and medications that are have anti-inflammatory action.

More Isn't Better

Aspirin can help prevent a stroke if you have certain risk factors, but taking more aspirin pills does not provide an increased benefit when it comes to stroke prevention.  The consistent use of daily aspirin in the dose recommended by your doctor is the safest way to take aspirin for stroke prevention.


Antiplatelet Agents for Stroke Prevention, Samuel Yip and Oscar Benavente, Neurotherapeutics, June 2011

The role of aspirin in women’s health, Freek WA Verheugt and Antoinette C Bolte, International Journal of Women’s Health, June 2011

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