Heart failure occurs if the heart muscle is not able to pump enough blood to meet the body's needs. The blood begins to back up because the heart is not pumping well and the veins, tissues, and lungs become congested with fluid. At first, pressure in the heart rises and blood and fluid back up into your lungs. You will feel short of breath and get tired easily. If the condition gets worse, the higher pressure causes a buildup of fluid in your veins. Your feet, legs, and ankles will begin to swell. The body cannot get rid of this fluid.  Heart failure is one of the most common causes of heart-related illness and death in the US.

Heart failure may result from coronary artery disease, a heart attack, years of untreated high blood pressure, damage to the heart valves, excessive alcohol consumption, and severe lung disease.  

The following factors may worsen or trigger heart failure in people with weakened hearts:

• severe anemia
• hyperthyroidism or hypothyroidism
• high fever
• a fast heartbeat
• too much salt in the diet
• drinking too much fluid
• working your body too hard
• emotional stress.