Myocarditis is a serious but rare heart condition that impacts 10 to 20 out of every 100,000 Americans. For comparison, coronary artery disease, which is the most common heart disease in the U.S., affects 100 out of every 100,00 people. In this Mayo Clinic Minute, Dr. Leslie Cooper, a Mayo Clinic cardiologist, explains what myocarditis is and why knowing the risk factors is so important.

“Myocarditis is simply inflammation of the heart muscle. It affects mostly younger adults, and it’s generally caused by a virus,” says Dr. Cooper.

The most common symptom of myocarditis is chest pain.

“In an otherwise healthy person, sometimes—a week or so after a viral-type illness—chest pain will develop, sometimes with shortness of breath, and it can be very disabling. It can occur at rest or with activity,” says Dr. Cooper.

Often myocarditis improves on its own with or without treatment. The treatment focuses on the cause and symptoms, such as heart failure.

“In that setting, we always treat heart failure with guideline-directed medications. But the chest pain specifically can be treated with anti-inflammatory medicines.”

Because testosterone is a driver of inflammation, which can make a viral infection more severe, young men tend to be more affected and tend to have more severe diseases.

Dr. Cooper says awareness of myocarditis symptoms and risk factors is important.

“If you develop symptoms of chest pain without any explanation or shortness of breath, particularly after a viral-type illness, it’s important to seek medical care promptly,” says Dr. Cooper.