Aspirin is used: as an anti-inflammatory analgesic which can relieve pain and swelling, to bring down high body temperatures, to prevent recurrence of heart attacks or strokes by thinning the blood. If someone who has previously had a heart attack or stroke takes Aspirin 300mg regularly, it reduces the risk of a blood clot occurring in the heart or brain. This can prevent further heart attacks or strokes. Always read the leaflet before the use of medication.