What Causes Congestive Heart Failure?
Congestive heart failure (CHF) usually develops slowly—due to some type of damage to the heart muscle.
The damage can be caused by a number of things, including:
- Scar tissue from a heart attack.
- Hardening of the arteries.
- Untreated high blood pressure.
- Diseases of the heart valves (usually from rheumatic fever).
- Birth defects.
- Diseases of the heart muscle.
- Severe lung disease.
- Uncontrolled diabetes.
- Toxic exposure to drugs or alcohol.
- Old age.
- Pregnancy. (In rare cases, CHF can develop shortly before or after a woman gives birth.)
- Viral infections.
- Severe anemia.
- Thyroid disease.
The term “heart failure" is misleading. The word failure makes it sound like the heart stops, or fails to function. But, that is not really the case. The heart keeps pumping, just not as well as it used to pump.
- The heart has two jobs. The first job is to continuously pump the de-oxygenated (used) blood to the lungs to pick up oxygen. (Every organ, every muscle, and every cell in the body needs oxygen to survive.)
- The second job is to pump that freshly oxygenated blood out of the heart and into the entire body to nourish all those muscles and organs.
With heart failure, oxygenated blood enters the left side of the heart from the lungs, but the ventricle can’t pump hard enough to push all the blood out to the body, so some is left behind. The blood backs up, causing fluid to leak back into the lungs. This is known as LEFT-SIDED HEART FAILURE.
When fluid backs up into the lungs, the client will have difficulty breathing. This is called pulmonary congestion.
Heart failure can happen on the right side, too. Blood enters the right ventricle as it should, but the ventricle can’t pump hard enough to get the blood into the lungs, so some is left behind. This is called RIGHT-SIDED HEART FAILURE.
The kidneys respond by causing the body to retain water and sodium. Fluid builds up in the legs, ankles, and feet. This is called edema.
The body becomes “congested” with fluid. This is why it is called “congestive” heart failure.
Over time, blood left behind stretches the ventricles, and they become even weaker, like a worn out rubber band.