There are several different types of heart failure. It may affect just one side of the heart — the oxygenated or deoxygenated side — or both sides.

Heart failure occurs when your heart muscle doesn't pump blood to the rest of your body the way it should. Learn about the causes and treatments.

Left sided heart failure is the most common form of congestive heart failure. It usually develops as a result of coronary artery disease. The left side of the heart is responsible for pumping blood to the rest of the body. In people with left sided heart failure, blood backs up into the lungs as the heart does not effectively pump it away. This issue can, in turn, cause shortness of breath and fluid buildup.

The right side of the heart pumps blood to the lungs, where it collects oxygen. Right sided heart failure typically follows left sided heart failure. However, it can sometimes occur due to other conditions, such as lung disease or pulmonary hypertension.

If heart failure affects only the oxygenated side of the heart, it is called left heart failure. If it involves just the deoxygenated side (which pumps blood to the lungs), it is called right heart failure. In biventricular heart failure, there are problems with both sides of the heart. Biventricular heart failure can occur with cardiomyopathy.

Diastolic heart failure occurs when the heart muscle is stiffer than usual but pumps normally. As the heart is stiff, it does not fill up with blood properly because it does not relax normally. Doctors refer to this as diastolic dysfunction. When the heart does not fill up with blood, this results in increased pressure inside the heart, which can cause a backup of fluid into the lungs.

Systolic dysfunction describes the heart’s inability to pump efficiently after filling with blood. It often occurs if the heart becomes weak or enlarged, which can occur on either side of the heart.