This disease begins with a throat infection caused by Group A streptococcus. It usually takes from 1 to 5 weeks (average is 19 days) after the strep symptoms have gone for Acute Rheumatic Fever to appear. Symptoms can persist for months and may reoccur at a later time if strep throat reoccurs.

The symptoms of Acute Rheumatic Fever include high fever, carditis (inflammation of the heart or its linings), polyarthritis (arthritis that affects more than one of the body's joints), and rashes (erythema marginatum). In addition, involuntary movements in the face, hands, or feet (known as chorea) may begin to occur some months after the acute phase of the disease has passed.

The most potentially serious affect of Acute Rheumatic Fever is the progressive damage it may cause to the heart, especially to the heart valves, and to other tissues in the body. These affects may not become apparent until years after recovery from the disease and may worsen during each recurrence of symptoms.

The aortic and mitral valves are the most commonly affected, and after recovery most commonly develop a range of valve stenosis and insufficiency.  Most often the valve insufficiency, if severe, is not repairable and will require replacement with a prosthetic valve.