If you cough a lot, often feel weak, have lost your appetite, and need to urinate a lot at night, you might have symptoms of heart failure. Heart failure is a long-term condition that usually comes on slowly. However, it can develop suddenly, for instance, after a heart attack. You have heart failure when your heart does not pump blood out of your heart very well, or when your heart muscles are stiff and do not easily fill up with blood. When you have heart failure, your heart cannot pump enough oxygen-rich blood to the rest of your body, especially when you exercise or move around a lot. As the heart loses the ability to pump blood, blood backs up in other parts of your body, including your lungs, liver, gastrointestinal tract, and your arms and legs. The most common cause of heart failure is coronary artery disease, the narrowing of the blood vessels that supply blood and oxygen to your heart. So, how do you know if you have heart failure? Get to your doctor. You may have trouble breathing, an irregular heartbeat, swollen legs, neck veins that stick out, and sounds from fluid built up in your lungs. Your doctor will check for these and other signs of heart failure. A test called an echocardiogram is often the best test to diagnose your heart failure. Your doctor can also use this test to find out why you have heart failure, and then monitor your condition going forward every three to six months. Your doctor will talk to you about knowing your body and symptoms that mean your heart failure is getting worse. You will need to learn to watch for changes in your heart rate, pulse, blood pressure, and weight. You will also need to limit salt in your diet, stop drinking alcohol, quit smoking if you need to, exercise, lose weight if you need to, and get enough rest. Your doctor will probably ask you to take medicines to treat your heart failure. These medicines can treat your symptoms, prevent your heart failure from getting worse, and help you live longer. If you have heart failure, taking your medicines, changing your lifestyle, and treating the condition that caused heart failure can go a long way toward improving your health. But heart failure is a chronic, or long-term, illness, which means it may get worse over time. Make sure you call your doctor if you start coughing more, have sudden weight gain or swelling, or feel week. Have someone take you to the emergency room right away if you have trouble with fainting, a fast and irregular heartbeat, or feel severe crushing chest pain.