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Diagnosis of Heart Failure

  • Michelle Badash, MS
Publication Type:

Condition InDepth

Diagnosis of Heart Failure

The doctor may suspect heart failure based on your medical history and symptoms, such as shortness of breath or edema. A complete physical exam will be done to look for other key signs of heart failure, such as:

  • Fluid in the lungs
  • The jugular vein in the neck has gotten larger
  • The liver has gotten bigger
  • High or low blood pressure
  • Rapid heart rate—known as tachycardia
  • Too much fluid in the belly cavity—ascites
  • Too much fluid in the space between the lungs and ribs—pleural effusion

Your doctor may advise tests to confirm the diagnosis and assess how much the heart is damaged. Some tests can also rule out other health conditions with symptoms that look like heart failure. Examples of these tests include:

  • Blood tests—to look for other issues, such as anemia, thyroid disorders, and high cholesterol. Blood tests can check how your kidneys and liver are working.
  • Brain natriuretic peptide (BNP)—there is more of this hormone in the blood when the heart is under strain. This is used as a sign of heart failure.
  • ECG—ECG records the electrical activity of your heart through 12 electrodes attached to the skin. This test will help diagnose heart rhythm problems, muscle problems, and damage to the heart from a heart attack.
  • Exercise stress test—This test looks at the heart's electrical activity during increased physical activity. It may be done with an echocardiogram or myocardial perfusion imaging. People who cannot exercise may be given IV medicines that simulates the effects of physical exertion.

Imaging tests take pictures of the heart, blood vessels, and structures. Imaging tests for heart failure include:

  • Chest x-ray—to see if the heart has gotten bigger or if there is fluid in the lungs
  • Echocardiogram—ultrasound to check how the heart's valves and chambers are working. This can also see how much blood is ejected from the heart with each heartbeat. An echocardiogram also can look for structural damage, tumors, or excess fluid around the heart.
  • Myocardial perfusion imaging—Contrast material is used to look at the heart muscle. Places with reduced blood flow can be seen on the scan.
  • Coronary angiography and coronary catheterization—These tests help find blockages in the heart's arteries and check heart function. Testing to check for blockage in those arteries is advised for some people with heart failure, such as younger people and people who have chest pain and angina.
  • CT angiography—Contrast material is used to look for places with reduced blood flow.
  • Electron-beam CT scan—makes images of the heart, lungs, and chest cavity
  • Cardiac MRI—looks at large blood vessels, coronary arteries, heart walls, and the pericardium, a double-walled sac that holds the heart.

Stages and Classes of Heart Failure

Once the diagnosis is made, your doctor will assess the stage and class of your heart failure.

Staging is based on heart damage and symptoms. The American Heart Association and American College of Cardiology Foundation stage heart failure as:

  • Stage A—have a high risk for heart failure but no symptoms of heart failure or heart disease
  • Stage B—heart disease without heart failure signs or symptoms
  • Stage C—heart disease with past or current heart failure symptoms
  • Stage D—heart failure that is not responding to standard treatment and needs more treatment

The New York Heart Association (NYHA) classifies heart failure based on symptoms and how they affect your abilities. NYHA classes are:

  • Class I (mild)—Ordinary activity does not cause symptoms. A person does not have limits on their physical activity.
  • Class II (mild)—Ordinary activity causes heart failure symptoms, but resting does not. Some physical activity has to be limited.
  • Class III (moderate)—Less than ordinary activity causes heart failure symptoms, but resting does not. A person has marked limits on their activity.
  • Class IV (severe)—A person cannot do any physical activity without having heart failure symptoms, or symptoms are present while resting.


  • Brain natriuretic peptide test (BNP). Children's Hospital of Philadelphia website. Available at: https://www.chop.edu/treatments/brain-natriuretic-peptide-test-bnp.
  • Diagnosing heart failure. American Heart Association website. Available at: https://www.heart.org/en/health-topics/heart-failure/diagnosing-heart-failure.
  • Heart failure with reduced ejection fraction. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/heart-failure-with-reduced-ejection-fraction.
  • How will I find out if I have heart failure? National Heart Lung and Blood Institute website. Available at: https://www.nhlbi.nih.gov/health/heart-failure/diagnosis.


  • Michael J. Fucci, DO, FACC
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.