What happens if someone has left heart failure?

Shortness of breath: Shortness of breath, dyspnea on exertion, paroxysmal nocturnal dyspnea, pedal edema, pulmonary edema.

Usually: This is a very complicated question, and we only have 400 characters, but it generally involves inadequate pumping function of the heart. This ultimately manifests with the buildup of fluid, usually in the lungs, belly and legs, and (in severe cases) decreases in blood pressure and the blood flow to vital organs like the kidneys. The whole process is called decompensation.