Side Effects of Low-Dose Aspirin

Low-dose aspirin is one of the most commonly prescribed medicines in the UK. It is often used to help prevent blood clots and reduce the risk of heart attack or stroke in people who are at higher risk. While it can be highly effective, low-dose aspirin, like all medicines, can cause side effects. Understanding these side effects can help you take aspirin safely and know when to seek medical advice.

This article explains the common and serious side effects of low-dose aspirin, who may be at higher risk, what to do if side effects occur, and when urgent medical help is needed. All information is based on guidance from the NHS.

What Is Low-Dose Aspirin?

Low-dose aspirin usually refers to doses between 75mg and 100mg per day. Unlike standard aspirin, which is often taken for pain relief, low-dose aspirin is primarily used as an antiplatelet medicine. This means it helps prevent blood cells called platelets from sticking together and forming clots.

Doctors commonly prescribe low-dose aspirin to people who have had a heart attack or stroke, those with certain heart or blood vessel conditions, or people with specific risk factors such as diabetes or high blood pressure.

Common Side Effects of Low-Dose Aspirin

Many people take low-dose aspirin without experiencing any side effects. However, some side effects are fairly common and occur in more than 1 in 100 people.

Mild Indigestion

One of the most common side effects is mild indigestion. This can include symptoms such as stomach discomfort, heartburn, or feeling slightly sick. Taking aspirin with food or after a meal may help reduce stomach irritation.

If indigestion persists or becomes uncomfortable, you should speak to your doctor or pharmacist for advice.

Increased Bleeding

Low-dose aspirin affects how blood clots, which means you may bleed more easily than normal. This can show up as bleeding gums, nosebleeds, or bruising more easily.

While minor bleeding is often not dangerous, ongoing or unexplained bleeding should always be discussed with a healthcare professional.

When to Speak to a Doctor or Pharmacist

If common side effects bother you or do not go away, it is important to talk to your doctor or pharmacist. They can help decide whether aspirin is still suitable for you or whether another treatment would be safer.

Never stop taking prescribed aspirin without medical advice, as this could increase your risk of serious health problems such as a heart attack or stroke.

Serious Side Effects of Low-Dose Aspirin

Serious side effects are rare, but they can happen. Knowing the warning signs is essential so you can act quickly.

You should call your doctor or NHS 111 immediately if you experience any of the following symptoms.

Signs of Internal Bleeding

Aspirin can sometimes cause internal bleeding. Warning signs include:

• Coughing up blood
• Blood in your urine, poo, or vomit
• Black or tarry stools

These symptoms require urgent medical assessment.

Signs of Liver Problems

Although uncommon, aspirin can affect the liver in some people. Signs may include:

• Yellowing of the skin or the whites of the eyes, which may be less noticeable on brown or black skin
• Darker than usual urine

If you notice these symptoms, seek medical advice promptly.

High Uric Acid Levels

Painful joints in the hands or feet can be a sign of increased uric acid levels in the blood. This may worsen conditions such as gout.

Swelling in Hands or Feet

Swelling of the hands or feet may be a sign of fluid retention. This should be checked by a doctor, especially if it appears suddenly or worsens.

Stomach Ulcers and Aspirin

One of the most serious risks of aspirin is the development of stomach or gut ulcers. This risk increases if aspirin is taken for a long time or at higher doses.

Your doctor may advise against taking aspirin if you currently have a stomach ulcer or have had one in the past. Symptoms of a stomach ulcer may include ongoing stomach pain, bloating, or feeling sick.

If you are at risk of stomach ulcers and need pain relief, paracetamol is usually recommended instead of aspirin, as it is gentler on the stomach.

Serious Allergic Reactions to Aspirin

In very rare cases, aspirin can cause a serious allergic reaction known as anaphylaxis. This is a medical emergency.

Call 999 immediately if you or someone else experiences:

• Sudden swelling of the lips, mouth, throat, or tongue
• Difficulty breathing or very fast breathing
• Wheezing or gasping for air
• A tight throat or difficulty swallowing
• Skin, lips, or tongue turning blue, grey, or pale
• Sudden confusion, drowsiness, or dizziness
• Fainting or collapse
• In children, limpness or unresponsiveness

A rash that is swollen, itchy, blistered, or peeling may also appear. Do not drive yourself to A&E. The emergency operator will tell you what to do next.

Other Possible Side Effects

The side effects listed here do not include all possible reactions to aspirin. For a complete list, you should read the patient information leaflet that comes with your medicine.

If you notice any unexpected symptoms while taking low-dose aspirin, report them to your doctor, pharmacist, or another healthcare professional.

Reporting Side Effects

You can help improve medicine safety by reporting suspected side effects through the Yellow Card scheme. This allows healthcare authorities to monitor medicines and identify new safety information.

Reports can be made online through the Yellow Card website.

Who Should Be Extra Careful With Aspirin?

Some people may be at higher risk of side effects from aspirin, including:

• People with a history of stomach ulcers or bleeding
• Those with asthma or allergies
• People with liver or kidney problems
• Older adults
• Those taking certain other medicines, including blood thinners

Always tell your doctor about all medicines and supplements you are taking before starting aspirin.

How to Reduce the Risk of Side Effects

To reduce the risk of side effects:

• Take aspirin exactly as prescribed
• Take it with food if advised
• Avoid alcohol or limit intake
• Do not take other painkillers without medical advice
• Attend regular check-ups if recommended

Following your doctor’s instructions carefully can help ensure the benefits of aspirin outweigh the risks.

Final Thoughts

Low-dose aspirin can be a life-saving medicine for many people, but it is not without risks. Understanding the possible side effects helps you make informed decisions about your health and ensures you know when to seek help.

If you ever feel unsure about your symptoms or your medication, speak to a healthcare professional. Prompt advice can prevent minor side effects from becoming serious problems.

Source

• NHS. Side effects of low-dose aspirin. Page last reviewed 16 December 2021. Next review due 16 December 2024.