People at high risk of heart attack should take a daily low-dose of aspirin (if told to by their healthcare provider) and that heart attack survivors regularly take low-dose aspirin.
You should not start aspirin therapy without first consulting your physician. The risks and benefits of aspirin therapy vary for each person.
Know the risks
Because aspirin thins the blood, it can cause several complications. Talk to your doctor if any of these situations apply to you. You should not take aspirin if you:
Have an aspirin allergy or intolerance
Are at risk for gastrointestinal bleeding or hemorrhagic stroke
Drink alcohol regularly
Are undergoing any simple medical or dental procedures
Preventing Heart Attack
Most heart attacks and strokes occur when the blood supply to a part of your heart muscle or brain is blocked. This usually starts with atherosclerosis, a process in which deposits of fatty substances, cholesterol, cellular waste products, calcium and other substances build up in the inner lining of an artery. This buildup is called plaque.
Plaque usually affects large and medium-sized arteries. Plaques can grow large enough to significantly reduce the blood's flow through an artery. But most of the damage occurs when a plaque becomes fragile and ruptures. Plaques that rupture cause blood clots to form that can block blood flow or break off and travel to another part of the body. This is called an embolism.
If a blood clot blocks a blood vessel that feeds the heart, it causes a heart attack.
If a blood clot blocks a blood vessel that feeds the brain, it causes a stroke.
Aspirin “thins” the blood and helps prevent blood clots from forming. So it helps prevent heart attack and stroke.
There is a risk of stomach problems, including stomach bleeding, for people who take aspirin regularly. Alcohol use can increase these stomach risks, so ask your doctor if it is safe for you to drink alcohol in moderation.
Should I take aspirin during a heart attack or stroke?
The more important thing to do if any heart attack warning signs occur is to call 9-1-1 immediately. Don't do anything before calling 9-1-1. In particular, don't take an aspirin, then wait for it to relieve your pain. Don't postpone calling 9-1-1. Aspirin won't treat your heart attack by itself.
After you call 9-1-1, the 9-1-1 operator may recommend that you take an aspirin. He or she can make sure that you don't have an allergy to aspirin or a condition that makes using it too risky. If the 9-1-1 operator doesn't talk to you about taking an aspirin, the emergency medical technicians or the physician in the Emergency Department will give you an aspirin if it's right for you.
Taking aspirin isn't advised during a stroke, because not all strokes are caused by blood clots. Most strokes are caused by clots, but some are caused by ruptured blood vessels. Taking aspirin could potentially make these bleeding strokes more severe.
The best way to know if you’re a candidate for aspirin therapy is to ask your healthcare provider. You should not start aspirin on your own.