Heart failure does not mean the heart has stopped working. Rather, it means that the heart is working less efficiently to meet the needs of the body. With heart failure, blood may move through the heart and body at a slower rate, and pressure in the heart increases. As a result, the heart cannot pump enough oxygen and nutrients to meet the body's needs. The chambers of the heart respond by stretching to hold more blood to pump through the body. This helps to keep the blood moving, but in time, the heart muscle walls may weaken and are unable to pump as strongly. As a result, the kidneys often respond by causing the body to retain fluid (water) and sodium. If fluid builds up in the arms, legs, ankles, feet, lungs, or other organs, the body becomes congested. Congestive heart failure is the term used to describe this condition.
The symptoms of heart failure are related to the changes that occur to your heart and body, and may be mild, moderate, or severe. The symptoms can include:
Congested lungs. Fluid backup in the lungs can cause shortness of breath with exercise or difficulty breathing at rest, which is often worse when lying flat in bed. Lung congestion can also cause a dry, hacking cough or wheezing.
Fluid and water retention. Less blood to your kidneys causes fluid and water retention, resulting in swollen ankles, legs, and abdomen (called edema) and weight gain. Symptoms may cause an increased need to urinate during the night. Bloating in your stomach may cause a loss of appetite or nausea.
Dizziness, fatigue, and weakness. Less blood to your major organs and muscles makes you feel tired and weak. Less blood to the brain can cause dizziness or confusion.
Rapid or irregular heartbeats. The heart beats faster to pump enough blood to the body. This can cause a fast or irregular heartbeat.
If you have heart failure, you may have one or all of these symptoms or you may have none of them. In addition, your symptoms may not be related to how weak your heart is; you may have many symptoms but your heart function may be only mildly weakened. Or you may have a more severely damaged heart but have no symptoms.