I No limitation

Ordinary physical activity does not cause undue tiredness, shortness of breath, or awareness of heartbeats (palpitations).

II Mild

Ordinary physical activity causes tiredness, shortness of breath, palpitations, or chest discomfort (angina).

III Moderate

The person is comfortable at rest, but ordinary physical activity causes tiredness, shortness of breath, and palpitations or chest discomfort (angina).

IV Severe

Symptoms occur at rest, and any physical activity increases symptoms.