Baby aspirin, the 81 mg low-dose tablet, is no longer recommended as broadly as it once was. Guidelines have narrowed significantly in recent years, and the people who genuinely benefit from a daily baby aspirin now fall into a few specific groups: adults aged 40 to 59 with elevated heart disease risk, people who have already had a heart attack or stroke, and pregnant people at high risk for preeclampsia.
Adults 40 to 59 With High Cardiovascular Risk
The U.S. Preventive Services Task Force (USPSTF) recommends that adults aged 40 to 59 consider low-dose aspirin if their estimated 10-year risk of cardiovascular disease is 10% or greater. This isn’t a blanket recommendation. The task force describes the net benefit as “small” and says the decision should be individualized, weighing your specific risk factors against the chance of bleeding complications.
You’re more likely to benefit if you have no history of stomach ulcers, recent bleeding episodes, or conditions that raise bleeding risk. Factors that push your 10-year cardiovascular risk above that 10% threshold include high blood pressure, high cholesterol, smoking, diabetes, and family history of heart disease. Free online calculators (search “ASCVD risk calculator”) can estimate your score using basic health numbers.
For people with type 2 diabetes specifically, the American Diabetes Association narrows the window further: aspirin for primary prevention in adults over 50 with diabetes who are at high cardiovascular risk, but not beyond age 70, where bleeding risk outweighs the heart benefit.
Why Adults Over 60 Should Not Start
This is the biggest shift from older guidelines. The USPSTF now recommends against starting baby aspirin for heart disease prevention if you’re 60 or older. The reasoning is straightforward: as you age, the risk of serious bleeding rises while the preventive benefit shrinks. The task force concluded with moderate certainty that initiating aspirin in this age group provides no net benefit.
The American College of Cardiology and American Heart Association landed in a similar place, with a soft upper boundary of 70 years. If you’re already taking daily aspirin and you’re over 60, that’s a different situation (more on stopping below), but the clear message is: don’t start now.
People Who Have Had a Heart Attack or Stroke
The strongest case for daily aspirin is in people who have already experienced a cardiovascular event. If you’ve had a heart attack, ischemic stroke, or transient ischemic attack (a “mini-stroke”), daily aspirin is a standard part of treatment to prevent a second event. This is called secondary prevention, and the evidence here is much more robust than for people trying to prevent a first event.
For stroke survivors specifically, guidelines recommend antiplatelet therapy, with aspirin at doses between 50 and 325 mg daily as one of the first-line options. Your cardiologist or neurologist may choose a different antiplatelet medication or a short-term combination depending on the type of event you had.
Pregnant People at Risk for Preeclampsia
Baby aspirin has a well-supported role in pregnancy that has nothing to do with heart disease. The USPSTF recommends 81 mg daily after 12 weeks of gestation for people at high risk of preeclampsia, a dangerous condition involving high blood pressure that can threaten both mother and baby.
You’re considered high risk if you have one or more of these factors:
- History of preeclampsia in a previous pregnancy
- Chronic high blood pressure
- Type 1 or type 2 diabetes diagnosed before pregnancy
- Kidney disease
- Autoimmune conditions like lupus or antiphospholipid syndrome
- Multiple pregnancy (twins, triplets)
A combination of moderate-risk factors can also qualify you. These include being a first-time mother, having a BMI over 30, being 35 or older, having a family history of preeclampsia, pregnancies conceived through IVF, or a gap of more than 10 years between pregnancies. Black women face elevated risk due to systemic health inequities that affect care access and health exposures.
How Baby Aspirin Works
Aspirin permanently disables an enzyme in platelets, the tiny blood cells responsible for clotting. Once that enzyme is knocked out, the platelet can no longer produce a chemical called thromboxane A2, which normally triggers clot formation. Because platelets have no nucleus and can’t make new proteins, the effect lasts the entire lifespan of each platelet. Your body replaces about 10% of its platelets per day, which is why a single small daily dose is enough to keep clotting suppressed.
This is also why aspirin carries bleeding risk. The same mechanism that prevents dangerous clots in narrowed arteries also makes it harder for your body to stop normal bleeding, whether from a stomach ulcer or a minor injury.
The Bleeding Tradeoff
Among people taking low-dose aspirin, major gastrointestinal bleeding occurs at a rate of roughly 3.5 events per 1,000 people per year. Intracranial bleeding (bleeding in or around the brain) is rarer, at about 0.6 events per 1,000 people per year. Those numbers sound small, and they are for any individual, but across millions of people taking aspirin daily, they add up. This is precisely why the guidelines have pulled back from recommending aspirin broadly: for people at low or moderate cardiovascular risk, the chance of a bleeding event can equal or exceed the chance of preventing a heart attack.
Certain things raise your bleeding risk further: a history of stomach ulcers, regular use of anti-inflammatory painkillers like ibuprofen, heavy alcohol use, being on blood thinners, or being over 60.
Don’t Stop Without a Plan
If you’ve been taking daily aspirin for a year or more, stopping abruptly can be risky. A large Swedish study of over 600,000 long-term aspirin users found that people who discontinued the drug experienced a 37% increase in cardiovascular events. That translates to roughly one additional heart attack or stroke for every 74 people who stopped each year. The increase was even steeper, 46%, among people taking aspirin for secondary prevention after a prior heart attack or stroke.
The spike in events appears to involve a rebound effect: once aspirin is removed, platelet activity surges as thromboxane levels climb back up, temporarily creating a state where clots form more readily than they did before you ever started aspirin. Even among patients who stopped aspirin because of a bleeding stomach ulcer, research found that staying on aspirin was safer overall than withdrawing it. If you and your doctor decide aspirin is no longer right for you, the transition should be planned and gradual rather than an abrupt stop.