Daily Aspirin Guidance: Is Taking An Aspirin Every Day Still Safe?

For decades, taking a daily low-dose aspirin was widely regarded as simple, effective insurance against heart attacks and strokes. However, evolving clinical research, updated guidelines from NICE, and new 2026 medical consensus statements have shifted how doctors evaluate this common habit. While daily aspirin remains vital for patients with a history of cardiovascular events, taking it purely for primary prevention can carry a risk of internal bleeding that outweighs its protective benefits.

I thought I’d mention this because it is something people have been asking me about recently.

If you are getting older, have high blood pressure or cholesterol, or simply want to reduce your chances of having a heart attack, a daily low-dose aspirin has been regarded as a fairly harmless bit of insurance. I suspect quite a few people reading this have a packet of 75mg or 100mg aspirin somewhere in the bathroom cabinet.

But there is a problem with that apparently simple little tablet.

As I’m sure you know, aspirin can cause bleeding. And as our understanding of cardiovascular disease has improved, doctors have increasingly had to ask a rather uncomfortable question: Is the benefit of taking aspirin every day actually greater than the risk?

The answer depends very much on who you are.

Primary vs. Secondary Prevention: Who Actually Benefits from Aspirin?

The first thing to understand is the distinction between what doctors call primary and secondary prevention. If you have already had a heart attack, a stroke, or certain other forms of cardiovascular disease, aspirin may be prescribed to reduce the risk of another event. That is secondary prevention, and aspirin remains an important drug for many patients in that situation.

The controversy is about primary prevention – taking aspirin when you have never had a heart attack or stroke, but are taking it in the hope that it will stop one happening. And this is where the medical advice has changed.

In the UK, NICE (the organisation that looks at the use of medicines) no longer recommends routinely using aspirin for primary prevention. European guidance has also moved away from routine aspirin in people who do not already have cardiovascular disease because of the increased risk of major bleeding. But before those of us living in Spain start feeling smug about the British changing their minds, there is another twist.

Spain is moving in much the same direction. In 2025, the Spanish Society of Family and Community Medicine, reported on a review of 38 clinical guidelines and identified routine aspirin use for primary prevention as a practice of little or no preventive value because of the increased risk of bleeding.

So, this isn’t really a case of Britain saying one thing and Spain saying another. The science behind prescribing is changing in both countries. The problem is that medical practice doesn’t always change overnight.

How Aspirin Works in the Bloodstream and Causes Bleeding Risks

The reasoning behind aspirin was perfectly logical. Aspirin interferes with platelets – the tiny components of our blood that help form clots. A clot forming inside a coronary artery can block the blood supply to the heart and cause a heart attack. So, if aspirin makes the blood less likely to clot, surely it should reduce heart attacks?

Yes, it does.

The difficulty is that the same mechanism can also cause unwanted bleeding.

Aspirin doesn’t know whether the clot it is preventing is a dangerous one blocking an artery or the perfectly useful clot that would normally stop a small blood vessel in your stomach or intestine from bleeding. Consequently, aspirin can increase the risk of gastrointestinal bleeding and, more rarely but more seriously, bleeding inside the brain.

For somebody who has already had a heart attack, preventing another potentially fatal clot may be worth accepting that risk.

For somebody who has never had cardiovascular disease, the calculation is very different.

And that is the bit that has changed.

Ageing, Cardiovascular Prevention, and Updated 2026 Guidelines

There is another irony here. Many of us were originally told about daily aspirin as we got older because our risk of heart disease increases with age. But age also increases the risk of bleeding.

So, the very group that might theoretically gain more protection from aspirin is also the group in which the unwanted effects become more important.

Modern cardiovascular prevention has also changed the equation. We are much better at controlling blood pressure and cholesterol than we were several decades ago. Statins, better treatment of hypertension, smoking cessation and improved management of diabetes have all reduced cardiovascular risk.

That means the additional benefit obtained by giving aspirin to somebody who is otherwise receiving good preventive treatment may be relatively small.

A large body of evidence shows this rather neatly: aspirin can reduce some heart attacks and strokes in people without previous cardiovascular disease, but it also increases major bleeding, and it has not been shown to reduce overall mortality in this setting. A 2026 American College of Cardiology scientific statement describes the benefit as modest and stresses that aspirin should not be used routinely for primary prevention, particularly in older people.

In other words, we have become better at preventing heart attacks without necessarily needing aspirin to do it.

Should You Stop Taking Aspirin? Important Medical Considerations

This is where I would strongly urge caution.

If you are already taking aspirin because you have previously had a heart attack, stroke, coronary stent or another cardiovascular event, do not simply stop taking it because you have read this article. The reason you were prescribed it may be very important.

Equally, if you have been taking aspirin for years because someone once told you that it was a good idea “at your age”, it is reasonable to ask your doctor whether that advice still applies to you.

There is no universal answer.

Your doctor needs to consider your cardiovascular risk alongside your bleeding risk. Have you had cardiovascular disease before? Do you have high blood pressure, diabetes or high cholesterol? Do you smoke? Do you have a history of stomach ulcers or gastrointestinal bleeding? Are you taking other medicines that increase bleeding risk? These are much more important questions than simply asking whether you are over a particular age.

And please don’t confuse aspirin with anticoagulant medicines such as warfarin or the newer direct oral anticoagulants. They work differently and are prescribed for different reasons.

Deprescribing Trends and Modern Medical Practice in Spain

For those of us living here, there is an important practical point. Spain has not suddenly announced that everybody taking aspirin should stop.

Rather, Spanish medical organisations are increasingly saying that routine aspirin for primary prevention is not justified because the potential harm from bleeding can outweigh the cardiovascular benefit.

There is even Spanish research published in 2026 looking specifically at deprescribing aspirin – in other words, helping patients who were taking it for primary prevention to come off it when there was no longer a good reason for doing so.

That tells us something quite important. The question is no longer simply whether aspirin works. It clearly does.

The question is whether you are likely to gain enough from it to justify the risks.

Evolving Science: Asking Your Doctor the Right Questions

I think there is a wider lesson here that applies to much of modern medicine. Sometimes treatments become part of medical culture.

Doctors prescribe them. Patients expect them. We get used to taking them. And after twenty or thirty years it can be surprisingly difficult to question whether they are still necessary. But medical science doesn’t stand still. What was sensible advice in 1985 may not necessarily be sensible advice in 2026.

That doesn’t mean the doctors who prescribed aspirin all those years ago were wrong. They were working with the evidence available to them at the time.

Nor does it mean aspirin has become a dangerous or useless drug. Far from it. For some people it remains an extremely important medicine. What has changed is our understanding of who is most likely to benefit.

So, if you are taking a daily aspirin, don’t panic and don’t throw the packet in the bin. Instead, ask a much more useful question at your next appointment:

“Why am I taking this, and does the benefit still outweigh the risk for me?”

That, ultimately, is what good medicine should be about – not giving everybody the same answer, but making sure that the treatment is right for the individual.

And perhaps that little white tablet deserves rather more thought than we once gave it.

The information provided in this column is for educational and informational purposes only, and does not constitute medical advice. It is not a substitute for a professional medical consultation, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health provider with any questions you may have regarding a medical condition.

Dr Marcus Stephan