The symptoms of heart failure can vary from person to person. They may start suddenly or develop gradually over weeks or months.Main symptomsThe most common symptoms of heart failure are:breathlessness – this may occur after activity or at rest; it may be worse when you're lying down, and you may wake up at night needing to catch your breathfatigue – you may feel tired most of the time and find exercise exhaustingswollen ankles and legs – this is caused by a build-up of fluid (oedema); it may be better in the morning and get worse later in the dayfeeling lightheaded and faintingLess common symptomsOther symptoms of heart failure can include:a persistent cough, which may be worse at nightwheezinga bloated tummyloss of appetiteweight gain or weight lossconfusiona fast heart ratea pounding, fluttering or irregular heartbeat (palpitations)Some people with heart failure may also experience feelings of depression and anxiety.Chest pain.Fainting or severe weakness.Rapid or irregular heartbeat with shortness of breath, chest pain or fainting.Sudden, severe shortness of breath and coughing up white or pink, foamy mucus.These symptoms may be due to heart failure. But there are many other possible causes. Don't try to diagnose yourself.At the emergency room, health care providers do tests to learn if your symptoms are due to heart failure or something else.Call your health care provider right away if you have heart failure and:Your symptoms suddenly become worse.You develop a new symptom.You gain 5 pounds (2.3 kilograms) or more within a few days.