What it is used for
- Mild to moderate pain such as headache, toothache and muscle pain
- Fever
- Inflammation
- At low doses, to help prevent blood clots, heart attack or stroke in people advised to take it by a doctor
How it works
Aspirin blocks the COX enzymes that make prostaglandins, easing pain, fever and inflammation. At low doses it also makes platelets less sticky for the life of the platelet, which reduces clot formation — the basis of its heart-protective use.
How it is taken
Comes as standard, soluble/dispersible, chewable and enteric-coated (gastro-resistant) tablets, and is also found in some combination cold and pain products. Take it exactly as your doctor, pharmacist or the label directs. Low-dose aspirin for heart or stroke protection should only be taken on a clinician's advice, not self-started.
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 stomach irritation
- Nausea
- Mild, easier bruising or bleeding
- Ringing in the ears with higher doses
Serious effects — get help
- Stomach or gut bleeding (black stools, vomiting blood or coffee-ground material, severe abdominal pain)
- Signs of a serious allergic reaction or asthma flare (swelling, wheezing, difficulty breathing)
- Bleeding that is hard to stop, or signs of bleeding in the brain (sudden severe headache, weakness, confusion)
- Reye's syndrome in children — aspirin is generally not given to under-16s with viral illness
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 NSAIDs and blood thinners (much higher bleeding risk)
- Other antiplatelet drugs
- Some blood pressure medicines and diuretics
- Methotrexate
- Corticosteroids and SSRIs (bleeding risk)
- Alcohol (stomach irritation)
Who should take care
- Not recommended in children and teenagers under 16 with fevers or viral illness due to the risk of Reye's syndrome, unless a doctor specifically prescribes it
- Generally avoided in pregnancy, especially late pregnancy, unless prescribed (e.g. specific low-dose use under specialist care) — ask your clinician
- Tell your doctor about ulcers, asthma, bleeding disorders, gout, or kidney or liver problems
- Stop and seek advice before surgery or dental work if you take it regularly
- Seek urgent care for signs of bleeding or allergic reaction