Aspirin is used to reduce pain, inflammation (swelling), and fever. Doctors may also give their patients aspirin to treat or prevent angina, heart attacks, transient ischemic attacks (also called TIAs or "mini-strokes"), and stroke.

 What is aspirin?

Aspirin is a type of medicine called a salicylate. Aspirin is used to reduce pain, inflammation (swelling), and fever. Doctors may also give their patients aspirin to treat or prevent angina, heart attacks, transient ischemic attacks (also called TIAs or “mini-strokes”), and stroke.

How does aspirin work?

Aspirin is an “antiplatelet,” which means that it stops blood cells (called platelets) from sticking together and forming a blood clot. That is why some patients who are recovering from a heart attack are given aspirin—to prevent further blood clots from forming in the coronary arteries. (See also Antiplatelet Therapy on this website.) Aspirin also reduces the substances in the body that cause pain and inflammation.

How much do I take?

There are many different kinds and strengths of aspirin. The amount of aspirin that you should take may vary. Talk to your doctor or pharmacist for more information about how and when to take aspirin.

What if I am taking other medicines?

Other medicines that you may be taking can increase or decrease the effect of aspirin. These effects are called an interaction. Be sure to tell your doctor about every medicine and vitamin or herbal supplement that you are taking, so he or she can make you aware of any interactions.

The following are categories of medicines that can increase or decrease the effects of aspirin. Because there are so many kinds of medicines within each category, not every type of medicine is listed by name. Tell your doctor about every medicine that you are taking, even if it is not listed below.

  • Other over-the-counter or prescription medicines that contain aspirin
  • Acetaminophen
  • Ibuprofen
  • Ketoprofen
  • Naproxen
  • Medicines for diabetes or high blood pressure
  • Corticosteroids
  • Anticoagulants

While taking aspirin, you should avoid drinking alcohol, because alcohol combined with aspirin can damage the lining of your stomach. Also, tell your doctor or dentist that you are taking aspirin before you have any kind of surgical or dental procedure. Aspirin reduces the blood’s ability to clot, and taking aspirin before surgical or dental procedures can lead to excess bleeding.

What else should I tell my doctor?

Talk to your doctor about your medical history before you start taking aspirin regularly. The risks of taking the medicine need to be weighed against its benefits. Here are some things to consider if you and your doctor are deciding whether you should take aspirin.

  • You have an allergy to aspirin.
  • You are thinking of becoming pregnant, you are pregnant, or you are breast-feeding your baby.
  • You have hemophilia.
  • You have Hodgkin’s disease.
  • You have a stomach ulcer, a bleeding ulcer, or other stomach problems.
  • You have kidney or liver disease.
  • You have heart disease or  congestive heart failure.
  • You have high blood pressure.
  • You have asthma.
  • You have gout.
  • You are or ever have been anemic (low red blood cell count in the blood)
  • You have nasal polyps.

What are the side effects?

Sometimes a medicine causes unwanted effects. These are called side effects. Not all of the side effects for aspirin are listed here. If you feel these or any other effects, you should check with your doctor.

Less common side effects:

  • Heartburn
  • Upset stomach
  • Ringing in the ears

Rare side effects:

  • Allergic reaction
  • Abdominal cramps
  • Throwing up
  • Dark or bloody stools or blood in the urine
  • Fever
  • Confusion or hallucinations

Again, tell your doctor right away if you have any of these side effects. Do not stop taking your medicine unless your doctor tells you to. If you stop taking your medicine without checking with your doctor, it can make your condition worse.

Do not give aspirin to a child or teenager to treat chickenpox or the flu without talking to a doctor first. Giving aspirin to children and teenagers may increase the risk of Reye’s syndrome, which can lead to brain and liver damage.

A consumer-based site by the American Society of Health-System Pharmacists that provides information about all types of medicines as well as safety tips for their proper use. The site’s search feature lets users search medicines by the brand or generic name.


The information in this Medicines for Cardiovascular Disease section has been taken from a number of sources. It is meant to give you information about certain medicines, but it does not cover all of the possible uses, warnings, side effects, or interactions with other medicines and vitamin or herbal supplements. This information should not be used as medical advice for individual problems. Please talk to your doctor and/or your pharmacist for prescription instructions.