Aspirin is a medicine often prescribed to treat atherosclerosis. This condition affects your arteries. These are the blood vessels that carry blood away from your heart out to your body. Having atherosclerosis means you're at greater risk of a heart attack or stroke. Aspirin can help prevent these from happening.

A fatty material (plaque) can build up in your arteries. This plaque makes it harder for blood to flow through them. A blood clot can then form on the plaque. It may block the artery, cutting off blood flow. This can cause conditions such as coronary artery disease (CAD) and peripheral arterial disease (PAD).

• CAD occurs when plaque builds up in the coronary arteries. These arteries supply the heart with oxygen-rich blood. This can lead to a heart attack.
• PAD occurs when plaque forms in leg arteries.

The same things that cause CAD and PAD can also cause plaque to form in other arteries in your body, such as those in the brain. When plaque occurs in the brain, it raises your risk of stroke.

Aspirin is a type of blood thinner called an antiplatelet. Antiplatelets prevent your blood cells from clumping together, thereby stopping clots from forming. This reduces the risk of blockage. Aspirin can be taken daily if you are at high risk of or have already had a heart attack or stroke. It's also used after a procedure called a stent placement. During this procedure, a doctor places a tiny wire mesh tube, or stent, into an artery to keep it open. Aspirin helps prevent blood clots from forming on the stent.

Tell your doctor about any medicines you are taking. This includes:

• All prescription medicines.
• Over-the-counter medicines.
• Herbs, vitamins, and other supplements.

Also mention if you have a history of ulcers or bleeding problems. Ask whether you will need to stop taking aspirin before having surgery or dental work. Always take medicines as directed.

• Have a routine. For example, take aspirin with the same meal each day.
• Don't take more than prescribed. A low dose gives the same benefit as a higher one, with a lower risk of side effects.
• Don't skip doses. Aspirin needs to be taken each day to work well.
• Keep track of what you take. A pillbox with days of the week can help, especially if you take several medicines. Or use a list or chart to keep track.

Side effects of aspirin are not usually serious. If you do have problems, changing your dose may help. Contact your doctor if you have any of the following:

• Excessive bruising (some bruising is normal)
• Nosebleeds, bleeding gums, or other excessive bleeding
• An upset stomach or stomach pain