Congestive heart failure (CHF), or heart failure, is a condition in which the heart can t pump enough blood to the body s other organs. The failing heart keeps working but not as efficiently as it should. People with heart failure can t exert themselves because they become short of breath and tired. This often occurs when they get too much fluid in their system and the body can t circulate it properly. It gets backed up in their lungs (causing shortness of breath) and their extremities (causing swelling)