aspirin - Have you ever had a headache? Chances are you have; almost all of us do once in a while. And chances are you took some kind of medicine to ease your headache. That medicine was most likely a relative of aspirin. You may also have taken aspirin or its relatives for other problems, like inflammation (swelling of joints or other parts of the body) or fever. But did you know that about 80 billion aspirin tablets are taken per year for these problems, as well as many others? For example, millions of people take aspirin to help prevent heart attacks! There are good reasons a doctor might say, 'Take two aspirin and call me in the morning'! --howstuffsworks.com