Heart Failure Symptoms By Class and Stage

By Editorial Team

2 min read

Reviewed by: HU Medical Review Board | Last reviewed: November 2019 | Last updated: September 2021

Heart failure (HF) is a complex, chronic syndrome that gets worse over time. During the diagnostic process, physicians classify each case of heart failure. The American College of Cardiology/American Heart Association (ACC/AHA) and the New York Heart Association (NYHA) have complementary classification systems.^1-4

The ACC/AHA stages reflect the range from a high risk of developing heart failure to advanced heart failure and are associated with an approach to treatment plans.^1-4 The New York Heart Association clinical classifications of heart failure reflect the severity of symptoms or functional limits due to heart failure.^1-2 A diagnosis can have an assignment of a stage and a class.

Stages and classes defined

Heart failure (HF) is generally classified by the severity of a patient’s symptoms. The most common classification system is the New York Heart Association (NYHA) Functional Classification. There are four levels of clinical classification (Class I-II-III-IV) used to stratify both the presence of symptoms and limitations experienced during physical activity. The severity of symptoms is made by comparison to normal breathing, shortness of breath, and/or angina (chest pain or discomfort).¹

The symptoms of heart failure associated with function during physical activity are an important indicator of disease progression and prognosis.^1-2

Class I: No limitation of physical activity. Ordinary physical activity does not cause symptoms of HF.
Class II: Slight limitation of physical activity. Comfortable at rest, but ordinary physical activity results in symptoms of HF.
Class III: Marked limitation of physical activity. Comfortable at rest, but less than ordinary activity causes symptoms of HF.
Class IV: Symptoms occur even at rest; discomfort with any physical activity. Unable to carry on any physical activity without symptoms of HF.

Class I and II are typically categorized as mild heart failure, while class III and IV are considered more severe or advanced heart failure. A person can move back and forth between these classes based on their symptoms. When a patient has a heart failure exacerbation, they will have more symptoms and likely be a higher class, but when their symptoms are better controlled, they will fall into a lower class.^1-4

The American College of Cardiology/American Heart Association (ACC/AHA) complementary staging system defines four stages (Stages A,B,C,D).³

Stage A: High risk of heart failure but no structural heart disease or symptoms of heart failure (pre-heart failure)
Stage B: Structural heart disease but no symptoms of heart failure (pre-heart failure)
Stage C: Structural heart disease and symptoms of heart failure
Stage D: Refractory heart failure requiring specialized interventions

These stages reflect the symptoms and treatment plans for heart failure. They represent a progression; as HF worsens, a person’s condition may advance to the next stage of heart failure. The objective is that with treatment, progression through the stages may be delayed.⁴