What it is used for
- Preventing blood clots in people who have had a heart attack or stroke
- Protecting people with heart artery disease or after a stent or bypass
- Reducing the risk of clots in some people at high cardiovascular risk, when a clinician advises it
How it works
At low doses, aspirin makes platelets less able to clump together, so the blood is less likely to form clots inside narrowed arteries. This is different from the higher doses used for pain and fever.
How it is taken
Used for the heart as low-dose oral tablets, sometimes coated to be gentler on the stomach, generally taken once a day with or after food. Take it exactly as your doctor directs and as written on the label. Do not start daily aspirin for heart protection on your own - it should be a clinician's decision because of bleeding risks.
No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.
Common side effects
- Indigestion or mild stomach upset
- Easy bruising
- Nosebleeds or longer bleeding from small cuts
- Heartburn
Serious effects — get help
- Black/tarry stools, vomiting blood, or blood in urine (possible internal bleeding) - seek urgent care
- Sudden severe headache, weakness or vision change (possible brain bleed) - emergency
- Severe allergic reaction: facial or throat swelling, wheezing, widespread rash - especially in people with asthma or aspirin allergy
- Ringing in the ears or confusion (possible overdose) - seek urgent care
If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.
Interactions to watch
- Other blood thinners and antiplatelets (combined use raises bleeding risk)
- Anti-inflammatory painkillers (NSAIDs such as ibuprofen)
- Certain antidepressants (SSRIs)
- Some blood-pressure and diuretic medicines
- Alcohol in excess (raises stomach bleeding risk)
Who should take care
- Do not give aspirin to children or teenagers for fevers or viral illness because of the risk of a rare serious condition (Reye's syndrome)
- Tell your clinician about any stomach ulcers, bleeding problems or asthma
- Tell any doctor, dentist or surgeon you take daily aspirin before procedures
- Discuss with your clinician if pregnant or breastfeeding
- Do not combine with other blood thinners or regular NSAIDs without advice