Heart failure develops when your heart muscles can’t pump enough blood throughout your body to supply your tissues with adequate oxygen.

Left-sided systolic heart failure develops from damage, weakness, or stiffness to the muscles of your left atrium and left ventricle. Likewise, right-sided heart failure develops due to weakening of the muscles in your right atrium and right ventricle.

Left- and right-sided heart failure are associated with their own sets of symptoms. Some people have heart failure on both sides and develop both types of symptoms.

Learn more about how left- and right-sided heart failure are similar and different.

Although the term heart failure suggests your heart isn’t able to function at all, it actually means your heart muscles just aren’t functioning well enough to support your body’s needs. It develops when your heart muscles are either too weak or not elastic enough to pump blood properly. About 6.2 million people in the United States are living with heart failure.

Heart failure is usually a chronic and progressive condition, but it can develop quickly after a heart attack or other conditions that damage your heart. The most common cause of heart failure is coronary artery disease, which is a narrowing of the arteries that supply blood to your heart.

The flow of blood through your heart

To understand the different types of heart failure, it helps to know how your heart pumps blood:

  1. unoxygenated blood flows from your body’s veins into your right atrium and then your right ventricle
  2. unoxygenated blood flows from your right ventricle to your lungs
  3. oxygenated blood flows from your lungs to your left atrium and then your left ventricle
  4. oxygenated blood flows from your left ventricle to your body’s arteries to be circulated throughout your body

Types of heart failure

The American Heart Association divides heart failure into one of three categories based on the part of your heart that’s affected:

  1. Left-sided systolic heart failure. There are two types of left-sided heart failure:
    • Systolic failure. This is when your left ventricle isn’t able to contract normally and your heart can’t push an adequate amount of blood into circulation.
    • Diastolic failure. This means your left ventricle doesn’t relax properly due to stiffness and your heart doesn’t fill with enough blood between beats, or the pressure for the heart to function is very high.
  2. Right-sided failure. In right-sided heart failure, your right ventricle loses pumping power and blood backs up in your veins.
  3. Congestive heart failure. The term heart failure is sometimes used interchangeably with congestive heart failure.

Left-sided heart failure

Left-sided heart failure is more common than right-sided heart failure and is caused by dysfunction of your left ventricle. It most often occurs due to coronary heart disease, heart attacks, or long-term high blood pressure. Left-sided heart failure can cause right-sided heart failure.

Left-sided heart failure causes blood to build up in your pulmonary veins that carry blood from your lungs to your right atrium. This buildup of blood can cause breathing symptoms, such as:

  • trouble breathing
  • shortness of breath
  • coughing, especially during exertion
  • shortness of breath when lying down
  • sleeping on extra pillows at night

Right-sided heart failure

Right-sided heart failure most often develops from left-sided heart failure due to a backup of blood around your lungs that puts more stress on the right side of your heart. According to data from the European Society of Cardiology registry, right-sided heart failure only accounts for 2.2 percent of heart failure hospital admissions.

Right-sided heart failure leads to blood buildup in your veins, which in turn may lead to fluid retention and swelling. The legs are the most common area to develop swelling, but it’s also possible to develop it in your genitals and abdomen.

Common symptoms of right-sided heart failure include:

A variety of respiratory conditions can contribute to the development of right-sided heart failure. These include:

Left-sided heart failureRight-sided heart failure
Definitionyour left ventricle is unable to pump blood adequately and blood builds up in the veins of your lungsyour right ventricle can’t pump blood properly and fluid builds up, often causing swelling in your lower body or abdomen
Common causescoronary artery disease, heart attack, arrhythmia or long-term high blood pressureleft-sided heart failure, some lung diseases such as chronic obstructive pulmonary disease
Frequencymore commonless common
Hallmark symptomstends to cause lung congestion and symptoms that affect your breathingoften causes fluid retention in your legs or other parts of your body
Neck vein pressuremild or moderately raised blood pressure in your jugular veinseverely elevated blood pressure in your jugular that may cause veins in your neck to pop out

Left-sided heart failure is more common, and right-sided heart failure often results from left-sided heart failure. The European Society of Cardiology registry reports about 20 percent of cases of right ventricular failure being secondary to left-sided heart failure.

Risk factors for developing both types of heart failure include:

  • Age. Your risk of heart failure increases with age.
  • Ethnicity. In the United States, Black people are more likely to have heart failure than people of other ethnic backgrounds. They’re also more likely to have heart failure at a younger age.
  • Sex assigned at birth. Men tend to develop heart failure at a younger age than women.
  • Family history. You’re more likely to develop heart failure if a close family member has also been diagnosed with it.
  • Lifestyle factors. Consuming excessive alcohol consumption, drug misuse, smoking, and a poor diet all increase your chances of heart failure.
  • Medical conditions. Certain other medical conditions, such obesity, high blood pressure, and diabetes, increase your likelihood of heart failure. Some cancer treatments like chemotherapy and radiation also increase your risk.

Heart failure develops when your heart isn’t able to pump enough blood to adequately supply your tissues with oxygen. Most of the time, heart failure develops on the left side of your heart. Right-sided heart failure most commonly develops due to left-sided failure, but some lung or heart problems can also lead to right-sided failure.

Making lifestyle adjustments to improve your heart health can reduce your chances of developing severe complications. A healthcare professional can help you build a strategy for managing your heart failure and for treating any underlying conditions.