New York Heart Association (NYHA) classification of heart failure

Table 3.8-1. New York Heart Association (NYHA) classification of heart failure
Class	Functional capacity
I	No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, dyspnea, or palpitation.
II	Slight limitation of physical activity. The patient is comfortable at rest, but ordinary physical activity results in fatigue, palpitation, or dyspnea.
III	Marked limitation of physical activity. The patient is comfortable at rest, but less than ordinary activity causes fatigue, palpitation, or dyspnea.
IV	Any physical activity causes discomfort. Symptoms of heart failure may be present even at rest. Discomfort increases with any physical activity.
Based on The Criteria Committee of the New York Heart Association. Nomenclature and Criteria for Diagnosis of Diseases of the Heart and Great Vessels. 9th ed. Little, Brown & Co; 1994:253-256.