Myocarditis is inflammation of the heart muscle (myocardium). A wide range of infections and other problems can cause myocarditis, which often develops in people who are otherwise healthy. Myocarditis does not always produce symptoms; however, signs of myocarditis may include shortness of breath, lightheadedness, abnormal heartbeat, and others. Prompt treatment of infections is one of the best ways to prevent myocarditis. Follow the links below to find WebMD's comprehensive coverage about how myocarditis is contracted, what it looks like, how to treat it, and much more. Call your doctor right away if you have symptoms of myocarditis, especially if they follow an infection, and if your symptoms have gotten worse following a diagnosis of myocarditis.