Left- vs. Right-Sided Heart Failure: What You Should Know

Heart failure is a condition where the heart can’t pump enough blood to meet the body’s demands. The heart muscles are weakened, and they can’t work as effectively as before. When this happens, tissues throughout the body are deprived of oxygen and other crucial nutrients.

How Common Is Heart Failure?

In the United States alone, more than six million adults have been diagnosed with heart failure.

Heart failure is usually divided into two categories based on which side of the heart it mainly affects. The right side of the heart collects oxygen-depleted blood from the body and brings it to the lungs to be filled with fresh oxygen. The left side of the heart receives oxygen-rich blood from the lungs and sends it out to the rest of the body.

An illustration with information about left-sided vs. right-sided heart failure

Illustration by Jessica Olah for Verywell Health

While the end result is the same, symptoms can vary based on whether the right or left side of the heart is affected.

Left-Sided Heart Failure

Left-sided heart failure is the most common type of heart failure. When it happens, your heart has lost some of its ability to pump blood out to your body after it’s been re-oxygenated. Without oxygen, tissues and organs throughout your body don’t work as well or begin to lose their function.

As the left side of the heart loses its ability to push blood out of the heart, blood can back up. Since blood is carried by the pulmonary veins from the lungs to the left side of the heart, blood backing up from the left heart can produce lung congestion and tends to affect breathing.

Thus, left-sided heart failure can cause both respiratory symptoms and problems in the tissues or organs receiving the least amount of oxygen-rich blood.

The most common symptoms of left-sided heart failure include:

  • Shortness of breath
  • Coughing
  • Weakness, especially in the legs
  • Kidney problems or increased nighttime urination
  • Increased heart rate as the heart works harder to pump blood out

Left-sided heart failure is usually caused by coronary artery disease which can reduce blood flow to the heart muscle, heart attacks, or prolonged high blood pressure (hypertension).

Left-sided heart failure is further classified as systolic or diastolic failure, according to the condition of the heart muscle.

Systolic Failure

Systolic failure, or heart failure with a reduced ejection fraction, happens when the left side of the heart becomes weakened, and is unable to contract with enough force to eject a sufficient amount of blood out to the body.

What Is an Ejection Fraction?

An ejection fraction is a measurement, expressed as a percentage, of how much blood the left ventricle pumps out with each contraction. An ejection fraction of 60% means that 60% of the total amount of blood in the left ventricle is pushed out with each heartbeat. A normal ejection fraction is between 50% and 70%.

Organs like the kidneys require a certain amount of pressure as blood flows through them to work properly. A weak pump can reduce this pressure and in turn decrease the ability of other organs, like the kidneys, to do their jobs. This is how heart failure can lead to multiple organ failure and even death.

Diastolic Failure

Diastolic heart failure is also known as heart failure with a preserved ejection fraction. In this type of heart failure, the left side of the heart has become stiff and doesn’t relax well between beats.

While the heart’s pumping ability remains strong, the walls of the heart, particularly in the left ventricle, don’t relax enough to fill the chamber with an adequate amount of blood. So while the blood is pushed out of the heart forcefully, not enough is pumped with each beat.

Right-Sided Heart Failure

In right-sided heart failure, the heart loses some of its ability to move oxygen-depleted blood to the lungs to pick up new oxygen. Blood enters the right atrium from the body and flows to the right ventricle, which pumps the blood through the pulmonary artery to the lungs and the left side of the heart.

Right-sided heart failure is most often caused by left-sided heart failure. This is because, as blood backs up from the left side of the heart into the pulmonary artery, the right side of the heart has to work harder to move blood to the left side. However, right-sided heart failure can also occur even when the left side of the heart is apparently normal.

The causes of right-sided heart failure can include:

Right-sided heart failure usually follows left-sided heart failure, so it can be difficult to differentiate the symptoms of the two. However, right-sided heart failure is characterized by a buildup of fluid in the vessels leading to the heart. This can cause swelling, mostly in the legs, genital area, and abdomen.

What If Both Sides of the Heart Fail?

In severe cases or advanced heart failure, both sides of the heart can be affected. This is referred to as biventricular heart failure.


Heart failure treatment depends a lot on what type of heart failure you have and the degree of damage that has already been done. The most important thing you can do to manage heart failure is to make lifestyle changes like:

  • Control other chronic conditions like hypertension and diabetes
  • Eat a healthy diet
  • Quit smoking
  • Avoid alcohol and illicit drugs
  • Exercise
  • Lower your intake of fats and sodium

What Are the Stages of Heart Failure?

Each type of heart failure is classified into stages. There are four stages—A, B, C, and D—and once you progress from one stage to another, there is no going back. The key to managing heart failure is to make changes and adhere to treatment strategies that stop or slow the progression of your heart failure from one level to the next.

A number of medications may be used to increase the function of your heart. For right-sided heart failure, the following may be prescribed:

  • Medications for correcting problems that caused the heart failure, like hypertension
  • Diuretics like furosemide to reduce fluid buildup and swelling
  • Anticoagulants like warfarin to reduce clotting in stagnant blood that backs up in the right atrium
  • Medications to increase the pumping ability or elasticity of the heart
  • Implanted devices that help the heart pump more effectively

Left-sided heart failure requires slightly different treatments, including:

  • Diuretics to reduce swelling
  • Medications to control high blood pressure
  • Inotropic medications that can help your heart pump more effectively
  • Medications that reduce the strain on the heart and help it pump better like digoxin
  • Implanted devices or a pump to help supplement the work of the heart

As your heart failure progresses, you may need additional treatments to manage the complications of heart failure, including medications to help support your kidney function or lifestyle changes to cope with the fatigue and weakness that heart failure can cause.

Frequently Asked Questions

What is usually the first sign of left-sided heart failure?

Shortness of breath and fatigue are common, early symptoms of left-sided heart failure.

What is usually the first sign of right-sided heart failure?

Sudden weight gain or swelling, especially in your limbs, are usually early signs of right-sided heart failure.

How does left-sided heart failure lead to right-sided heart failure?

As the left side of the heart loses its ability to pump blood out to the body, blood backs up into the right side of the heart. The right side of the heart then has to work harder, compensating for the weakness in the left side. This heavier workload can lead to right-sided heart failure.


Left- and right-sided heart failure both ultimately lead to the organs and tissues in your body not receiving enough oxygen and nutrients, but the symptoms and treatment of each are slightly different. If you experience shortness of breath, fatigue, sudden weight gain, and swelling in your limbs, contact your doctor right away because these are early signs of heart failure.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Heart failure.

  2. Institute for Quality and Efficiency in Health Care. Types of heart failure.

  3. American Heart Association. Ejection fraction heart failure measurement.

  4. University of Michigan Health. Right-sided heart failure.

  5. Cleveland Clinic. Heart failure: understanding heart failure.

By Rachael Zimlich, BSN, RN
Rachael is a freelance healthcare writer and critical care nurse based near Cleveland, Ohio.