Heart failure occurs when

  1. Your heart does not squeeze with enough force, pumping 40% or less of the blood with each beat or
  2. Your heart fails to fully relax after ejecting blood (the heart is stiff).

Your heart muscle pumps blood to all organs in your body. When working properly, with each beat, your heart ejects more than half the blood from its chambers and then relaxes fully to allow new blood to enter.

If your heart is pumping 40% or less, you have systolic heart failure. Systole means “contraction” in Greek and refers to the time your heart contracts.

If your heart cannot relax completely, you have diastolic heart failure. Diastole means “a drawing apart” in Greek and refers to your heart’s period of relaxation.

Some patients have components of both systolic and diastolic heart failure. In either of these cases, excess fluid can back up into your lungs or other parts of the body – leading to certain symptoms.

Heart failure icon beating

Know the Symptoms

One of the first and more common signs of heart failure you may notice is weight gain. This can occur slowly or rapidly and is due to fluid accumulation in your abdomen (belly) and legs (usually ankles and feet).

If fluids accumulate in your lungs, you may also feel short of breath. You may have difficulty lying flat in bed and may need to sleep sitting up or with your head raised on several pillows. You may also feel easily fatigued, sometimes after basic activities like walking or eating. You might also lose your appetite.

Less commonly, you could develop more severe symptoms that need immediate attention. Ask someone to drive you to the emergency room, or call 911, if you experience:
- Struggling to breathe
- Unrelieved shortness of breath while sitting still
- Chest pain
- Confusion or inability to think clearly