Who Should Take Low-Dose Aspirin to Help Prevent Health Problems?

Can an aspirin a day keep the doctor away — or is it time to rethink that suggestion?

Years ago, aspirin was recommended for heart attack and stroke prevention for most men aged 50 and up. Women aged 65 and older were also thought to benefit. That’s because these conditions can be caused by blood clots, and aspirin is a blood thinner. 

But recent research has shed more light on the potential downsides, as well as upsides, of daily aspirin. Experts now know more about who can benefit from it — and who it could harm. Here, we’ll go through the current guidelines so you know if daily low-dose aspirin is right for you.

What is low-dose aspirin and how does it work?

Until about 1950, aspirin was mainly used for pain relief. But then scientists discovered that aspirin could make your blood less sticky. This meant that aspirin could also be used as a blood thinner. As a result, aspirin began to be used for treating and preventing heart attacks and strokes.

The idea of low-dose aspirin came about because experts wanted to use the lowest dose possible. That’s because aspirin can have some unwanted side effects. Low-dose aspirin is considered to be anywhere between 75 mg and 325 mg. But in general, 81 mg is what experts usually mean by low dose.

Is low-dose aspirin the same as ‘baby aspirin’?

It used to be common for kids to get low-dose aspirin — sometimes known as “baby aspirin” — for fevers and body aches. But aspirin is no longer recommended for people under the age of 16. That’s because kids who take aspirin during a viral illness are more likely to get a life-threatening condition called Reye’s syndrome. Reye’s syndrome can cause seizures and other neurological problems. So low-dose aspirin is no longer labeled as baby aspirin. 

Can low-dose aspirin help prevent heart attacks?

The short answer is yes: Low-dose aspirin can help prevent heart attacks in people who are at high risk.

But aspirin has some important downsides. It can cause stomach pain and bleeding, even at low doses. It also raises the chances of bleeding in the brain. This can happen if people fall and hit their head. It can also happen without any warning or accident. These problems are uncommon. But they can be life-threatening. So it’s important to know who benefits from low-dose aspirin, and if the possible benefits outweigh the risks.

To help decide who can benefit from aspirin, medical professionals look at whether someone potentially needs aspirin for primary prevention versus secondary prevention of a heart attack. 

Primary prevention

Primary prevention is about stopping heart disease before it even starts. 

Primary prevention is for people who are at risk for a heart disease but have never had a heart attack or a blocked heart artery. It also means they’ve never had a stroke or peripheral artery disease. Like heart disease, these conditions are usually caused by blocked arteries. 

So primary prevention is all about avoiding things that can lead to heart disease in the first place. It includes things like:

• A heart-smart diet 

• Regular exercise 

• Avoiding tobacco and nicotine

• Keeping blood sugar normal

• Having normal blood pressure

• Getting your cholesterol down

• Maintaining a healthy body weight

Some people are at higher risk than others. In the next section, we’ll talk more about how to use your personal health conditions to make a decision about aspirin.

What is secondary prevention?

Secondary prevention is for someone who already has heart or vascular disease but wants to stop it from getting worse. This can involve the same lifestyle changes that are used for primary prevention. But it may also include certain medications and even surgery. 

So, to sum up: Primary prevention is about stopping heart disease from happening at all. Secondary prevention is about making it better if it’s already there. 

Now we can tackle the question of who should take aspirin for heart attack and stroke prevention.

Who should take low-dose aspirin for heart attack and stroke prevention?

You may have heard different advice about who should take aspirin. As we mentioned, healthcare professionals used to believe that aspirin was a good idea for most people over the age of 50. But then more research was done, and the risk of bleeding problems became more clear. 

When thinking about aspirin, the benefits of taking it should outweigh the risks. So, if you are very unlikely to have a heart attack or stroke, then it’s not worth taking the risk of a serious bleeding event.

In 2022, the U.S. Preventive Services Task Force (USPSTF) put together all of the most recent research about aspirin and prevention. This is how it developed the latest guidelines, which are discussed below.

For primary prevention

• Aspirin is no longer recommended for people 60 or older who have never had heart disease, a stroke, or other blood vessel blockages. 

• Aspirin is recommended if you are between 40 and 59 years of age and you have a 10% or greater risk for developing heart disease over the next 10 years. 

Your healthcare provider can help calculate your 10-year risk, which takes into account your risk factors. They can also look at other health issues or inherited risks that might impact your choice. 

Even if you are in the group who could benefit, you will want to look at the pros and cons. This is especially true if you are at increased risk of one of the serious side effects, which we discuss in the next section.

Although it can prevent heart attacks, aspirin does not appear to prevent strokes in those who are at low risk.

For secondary prevention 

Most people who have had blocked arteries in the heart, brain, or legs should take aspirin daily. That includes both heart attacks and stents. But in some cases, you may be on a different type of blood thinner instead. And occasionally aspirin is used along with other blood thinners. It’s important to check with your healthcare provider if you are not certain about aspirin.

Aspirin side effects: Is it safe to take low-dose aspirin?

It’s a small pill, but aspirin can have a big impact on your health. Many people can take aspirin safely. But there are some important side effects to consider. These include:

• Easy bleeding and bruising

• Nausea and stomach pain

• Intestinal bleeding

• Heartburn, also known as gastroesophageal reflux disease (GERD)

• Ringing in the ears (tinnitus)

• Allergic reactions

If you have stomach problems or fall frequently, then your risk of bleeding from aspirin could be higher than normal. You will also want to look at the other medications that you take.

For example, NSAIDs like ibuprofen also increase your bleeding risk. That’s why it’s best not to combine them with aspirin. 

Most people taking other blood thinners should not take aspirin. But there are some cases where two or more blood thinners are combined.

Does low-dose aspirin offer benefits for other health conditions?

Aspirin is sometimes used for other conditions besides heart attacks. Those are mentioned briefly below.

Atrial fibrillation

Aspirin used to be prescribed to prevent blood clots in people with atrial fibrillation. But now we have better and safer options. In general, aspirin is no longer recommended for atrial fibrillation. If you have atrial fibrillation and take aspirin, check with your healthcare provider to be sure you are taking the best medication for your condition.

Blood clots

Orthopedic surgery can put you at risk for blood clots in the first few weeks of recovery. That’s especially true if you break your leg, pelvis, or hip. These clots are called DVT (deep vein thrombosis). It turns out that aspirin can help prevent clots in this situation. Your surgeon will be able to advise you about aspirin, including when you can safely start and stop it.

Long airplane flights can put some people at risk for DVT. So, is aspirin a good idea for travelers? For most people, aspirin is not recommended. Instead, moving your legs, stretching, and wearing compression socks is usually the best advice.

Preeclampsia

Preeclampsia is a complication of pregnancy that causes high blood pressure and abnormally high protein in the urine. It usually occurs in the last few months of pregnancy. Sometimes it happens after delivery.

The USPSTF recommends starting low-dose aspirin (81 mg per day) after 12 weeks of pregnancy in people who are at high risk of preeclampsia. It’s very important that you make this decision with your obstetrics healthcare provider. They will monitor you closely during the pregnancy and watch for any side effects.

COVID-19

Blood clots, including DVT, are common in people hospitalized with COVID-19. And people with COVID who get a blood clot are more likely to have other complications. That includes dying from the virus. 

There are ongoing studies to figure out how COVID causes clotting — and how to best treat it. But there is evidence that people with moderately severe cases of COVID-19 might benefit from aspirin.

Aspirin is only one part of the treatment for COVID. And if you get a serious blood clot, you will need stronger therapy. 

Colon cancer

There is evidence that aspirin may prevent some cases of colon cancer. But the USPTF report from 2022 states that the issue is not settled. One study even found that daily aspirin use may speed up the growth of undiagnosed colon cancer in older adults. 

The best ways to lower your risk of colon cancer include things like a healthy diet, exercise, not smoking, and limiting alcohol. These things will also protect your heart.

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Written by:

Sarah A. Samaan, MD

Sarah Samaan, MD, FACC, FACP, FASE is a board-certified cardiologist who practiced clinical cardiology for nearly 30 years. She is a member of the American College of Cardiology, the American College of Physicians, the American Society of Nuclear Cardiology, and the American Society of Echocardiography.

Edited by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

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