blood pressure

What Causes Heart Failure?

Many things can damage or weaken the heart enough to cause heart failure. In some cases you may know damage has been caused, but not always.

Coronary Artery Disease (CAD)

This is the most common form of heart disease and cause of heart failure.

  • CAD is caused by the steady buildup of a fatty substance (plaque) on the inside walls of your arteries. This process is called atherosclerosis (ath-uh-roh-skluh-roh-sis).
  • Atherosclerosis slows down how blood flows through your arteries. This can cause some areas of your heart muscle to become weak because they don't get as much blood as they need.
  • If not treated, plaque can break off and get stuck. This can cause a blood clot to form and block blood flow to the heart causing a heart attack. A heart attack can cause permanent damage to the heart.

High Blood Pressure

High blood pressure, or hypertension, is when there is increased pressure and stiffness in the walls of your arteries. A heart that pumps against this high pressure can weaken over time.

Other Possible Causes

Click on the "Learn More" button below to find out about other conditions that can put you at risk for heart failure. Having more than one can increase your risk even more.

  • Some people are born with heart defects, such as heart chambers or valves that haven't been formed fully or correctly.
  • This can cause the heart to work harder to pump blood, which can lead to heart failure if not fixed.
  • A heart attack happens when an artery that brings blood to your heart becomes blocked.
  • Blood carries important nutrients and oxygen — without it, the heart can be damaged.
  • When the heart is damaged, it doesn't pump blood as well.
  • Your heart has valves that keep the blood flowing in the right direction.
  • When a valve doesn't work correctly, your heart has to work harder to make up for blood flowing in the wrong direction. This causes the heart to weaken over time.
  • The heart can be damaged by alcohol, drug abuse, or even the effects of some types of chemotherapy and radiotherapy used to treat cancer. This is called cardiomyopathy.
  • Your genes and family history can also put you at greater risk for damage of the heart muscle.
  • Myocarditis is an infection that can also cause damage to the heart muscle.
  • The heart has to work harder when the lungs don't work as well as they should.
  • Over time, the right side of the heart, which pumps blood to the lungs, can become weakened, leading to heart failure.
  • An arrhythmia is an abnormal heart rhythm. It usually causes the heart to beat too fast or beat off rhythm.
  • Either way, the heart has to work harder, which can weaken it over time, leading to heart failure.
  • A high heart rate can be a risk factor for heart failure.
  • Diabetes is a condition that can happen if you don't have enough of a hormone called insulin to turn sugar in your blood into energy.
  • When diabetes is not controlled it can cause many health problems, including damage to the heart. This can eventually lead to heart failure.
  • The thyroid is a gland in the neck that makes hormones that help control your body.
  • Hyperthyroidism happens when your thyroid makes too many hormones for your body. Hypothyroidism happens when your thyroid makes doesn't make enough hormones.
  • Both types of thyroid disease can cause heart failure.
  • Additional risk factors include having obesity or being overweight.
  • Heavy smoking and alcohol use can also increase your risk for heart failure.
  • Sometimes there is no known cause for the heart failure.