Aspirin: What It Actually Does and When to Use It

Aspirin is one of the most common medicines people keep in a home cabinet. It can calm pain, lower a fever, reduce inflammation, and in low doses it helps prevent blood clots. That mix of effects makes aspirin useful for headaches and for people at risk of heart attack or stroke. But aspirin also raises bleeding risk, so it isn't for everyone.

If you take aspirin for heart protection, doctors usually recommend a low dose: 75–100 mg once daily. This "baby aspirin" reduces platelet stickiness and cuts clot risk. For short-term pain or fever, typical doses are 325–650 mg every four to six hours, but never exceed the packaging or your doctor's instructions. Always check with a healthcare professional before starting daily aspirin, especially if you take blood thinners, have ulcers, or plan surgery.

When to avoid aspirin

A quick rule: don't give aspirin to children or teenagers with a viral illness. That's linked to Reye's syndrome, a rare but serious condition that can harm the liver and brain. For pregnant women, aspirin in low doses is sometimes used under medical supervision for specific issues, but you should not self-prescribe while pregnant.

Interactions matter. Aspirin can increase bleeding when combined with anticoagulants like warfarin, with newer blood thinners, or with other antiplatelet drugs. NSAIDs such as ibuprofen can interfere with aspirin's heart-protective effect if taken at the same time; spacing doses helps, but ask your doctor for exact timing. Alcohol adds bleeding risk, especially with regular aspirin use.

Watch for common side effects: stomach pain, heartburn, and nausea. More serious signs include black stools, vomiting blood, severe headache, or sudden weakness—seek urgent care if these occur. Long-term use can irritate the stomach lining and cause ulcers. People with a history of stomach bleeding or active ulcers should avoid regular aspirin unless a doctor says otherwise.

Tips and monitoring

Regular aspirin users should get periodic checkups. Ask your doctor to check your blood count and liver function if you use aspirin long-term or at higher doses. If you notice easy bruising, frequent nosebleeds, or dark urine, tell your clinician. Also review all supplements and herbs you take—some, like ginkgo or fish oil, can increase bleeding risk.

Before adding aspirin, compare benefits and risks with a doctor. For many people over 70, the risks often outweigh the benefits.

If you can't take aspirin, there are alternatives depending on the goal. For pain, acetaminophen or other NSAIDs may work. For clot prevention, doctors may prescribe different antiplatelet or anticoagulant drugs based on your condition. Never swap or combine medications without medical advice.

Practical tips: take aspirin with food to reduce stomach upset; keep it in its original container; check the expiration date. If you're preparing for surgery or dental work, tell your provider about aspirin—many recommend stopping it several days beforehand. If you have questions about daily aspirin for heart disease prevention, a brief conversation with your doctor can clarify risks and benefits based on your age, blood pressure, cholesterol, and bleeding history.