Table 8

WHO functional classes

WHO Functional ClassDescription
Class ICan perform ordinary physical activity without symptoms.
Class IIOrdinary activity causes symptoms of dyspnea, fatigue, chest pain or near syncope. Comfortable at rest.
Class IIIMarked limitation of activity. Less than ordinary activity causes symptoms. Comfortable at rest.
Class IVCannot perform any activity without symptoms. Dyspnea and/or fatigue at rest.