What is the definition of Class III in the NYHA functional classification?

Class III in the New York Heart Association (NYHA) functional classification describes patients who experience moderate activity limitations. This means that individuals classified as Class III are comfortable at rest but have marked limitations in physical activity. They may become fatigued or experience symptoms such as dyspnea or chest pain with activities that are considered ordinary or routine for others, such as walking or climbing stairs. Therefore, patients can perform some activities but must do so with caution and may need to rest frequently, reflecting a significant impact on their functional ability.

The other classifications delineate different levels of limitation:

• Class I signifies no limitations, where an individual can perform normal activities without any symptoms.

• Class II indicates minimal activity limitations, where individuals may experience symptoms under greater levels of exertion than those who are in Class III.

• Class IV is for patients who exhibit severe limitations, even at rest, and may experience discomfort with any physical activity.