Heart Failure Symptoms by Stage and Class

Reviewed by: HU Medical Review Board | Last reviewed: February 2024

Heart failure (HF) is a complex, chronic condition that often gets worse over time. Heart failure means your heart is not pumping enough blood throughout your body.1

When you are diagnosed with heart failure, your doctor will measure the amount of disease you have. This is called staging. The stages of heart failure are a way to categorize how well your heart is working and how severe your heart failure is.1

Symptoms of heart failure

The most common symptoms of heart failure are:2

  • Fatigue
  • Shortness of breath
  • Rapid heart rate (heart palpitations)
  • Chest pain

However, other signs may also mean your body is not getting enough fresh oxygenated blood, including:2

  • Consistent coughing or wheezing
  • Buildup of fluid in the body (edema)
  • Lack of appetite
  • Nausea

It is important to talk to your doctor about all the symptoms you are feeling. Keeping a diary of your symptoms will also help your doctor understand how much and how often your symptoms are impacting your daily life.2

Why heart failure symptoms occur

Heart failure symptoms occur when the heart is unable to pump blood effectively, leading to a decrease in the heart's ability to meet the body's demand for oxygen and nutrients. This can lead to symptoms such as the ones listed above. Heart failure results from various underlying conditions that weaken or damage the heart muscle. Some common causes of heart failure include:3

  • High blood pressure
  • Previous heart attack
  • Coronary artery disease

Stages of heart failure

Heart failure stage measures how far along the disease has progressed. The American College of Cardiology (ACC) and the American Heart Association (AHA) define the 4 stages of heart failure as:1,4,5

  • Stage A – At risk of heart failure. People in stage A do not yet have symptoms, changes in the structure of the heart, or changes in how the heart works. Stage A includes people with high blood pressure (hypertension), vascular disease, diabetes, obesity, or a family history of certain heart conditions.
  • Stage B – Pre-heart failure. People in stage B have changes in the structure of the heart and other risk factors, but they do not have symptoms of heart failure.
  • Stage C – People in stage C have current or previous symptoms of heart failure.
  • Stage D – People in stage D have symptoms that interfere with daily life. They may need to go to the hospital to be treated for heart failure.

Classes of heart failure

Heart failure class measures the impact heart failure has on your life and what level of activity triggers symptoms. Once your heart failure reaches stages C or D, your doctor will also grade your disease by class. Most commonly, doctors use the classification system developed by the New York Heart Association (NYHA). It assigns 4 class levels based on how severe symptoms are.1,4

  • Class 1 – Regular activities do not cause unusual tiredness (fatigue), shortness of breath, or heart palpitations. There are no limits on physical activity.
  • Class 2 – The person is comfortable at rest. But regular activities cause symptoms like tiredness, shortness of breath, chest pain, or heart palpitations. There are a few limits on physical activity.
  • Class 3 – The person is comfortable at rest in this class too. But more ordinary activities cause more of the symptoms listed in class 2. There are more strict limits on physical activity.
  • Class 4 – Even at rest, the person shows signs of heart failure. In this class, any physical activity causes discomfort and symptoms.

Measuring how well the heart works

Doctors can determine how well your heart is working using tests that measure left ventricular ejection fraction (LVEF). Your heart has 4 chambers, and the left ventricle is the bottom chamber closest to your left arm. The left ventricle is the chamber that forces fresh blood full of oxygen through the body.5,6

In people with heart failure, the left ventricle does not pump blood out to the body as well as it should. An LVEF test measures the amount of blood in the left ventricle versus the amount of blood it pumps out.3,7

When your heart is working normally, between 50 and 70 percent of the blood is pumped out of the left ventricle. At 41 to 49 percent LVEF, you may begin to feel symptoms of heart failure, like shortness of breath. At 40 percent and lower, symptoms become more noticeable.7

It may be possible to improve your LVEF numbers by exercising and controlling the underlying causes of your heart failure. For instance, taking drugs to control your blood pressure and diabetes may help.7

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