The four stages of pulmonary hypertension are:
Class I: No symptoms during rest or when performing activities.
Class II: Presence of symptoms, such as fatigue or shortness of breath, during routine activities, except at rest.
Class III: Symptomatic and experiences fatigue, shortness of breath, and chest pain. People may also experience limitations in performing everyday activities.
Class IV: Symptoms occur at rest and during any physical activity.