Aspirin, also known as acetylsalicylic acid (ASA), is a salicylate medication, often used to treat pain, fever, and inflammation. Aspirin also has an antiplatelet effect by stopping the binding together of platelets and preventing a patch over damaged walls of blood vessels.Aspirin is also used long-term, at low doses, to help prevent heart attacks, strokes, and blood clot formation in people at high risk of developing blood clots.spirin is also used long-term, at low doses, to help prevent heart attacks, strokes, and blood clot formation in people at high risk of developing blood clots.