New York (NYHA) classification of heart failure
- Class I (Mild): Heart disease present, but no undue dyspnoea from ordinary activity.
- Class II (Mild): Comfortable at rest; dyspnoea on ordinary activities.
- Class III (Moderate): Less than ordinary activity causes dyspnoea, which is limiting.
- Class IV (Severe): Dyspnoea present at rest; all activity causes discomfort.