Heart failure (HF), also referred to as congestive heart failure, occurs when heart loses the ability to provide sufficient pump action to maintain blood flow. Most of the signs of a heart failure occur as a result of the congestion that develops as fluid, backing up into the lungs and leaking into the tissues. Other symptoms are a result of inadequate oxygen supply to the body's tissues.

The symptoms of severe heart failure include the following:

Shortness of Breath (Dyspnea)

Those who have severe heart failure risk may feel out of breath after exertion. Breathing difficulty can be triggered when climbing stairs or even walking around. They may feel severe pain in the chest or feel heaviness on the chest.

Patients may experience shortness of breath when they lie flat at night, referred to as orthopnea. They may feel the need to use more than one pillow underneath their head and shoulders to sleep.

Severe Paroxysmal nocturnal dyspnea (PND) is another common symptom of severe heart failure. It is characterised by a sudden episode that awakens one at night. The symptoms include severe shortness of breath, coughing or wheezing, which occurs 1-3 hours after going to sleep.

Fluid Retention (Edema) and Weight Gain

Patients may report foot, ankle, leg or abdominal swelling. Fluid retention that leads to sudden weight gain and increased urination are among common signs. There could be swelling in the veins of the neck in a few cases.

Wheezing or Cough

Patients may have dry cough and persistent wheezing a few hours after lying. The symptoms can be alleviated by sitting upright.

Loss of Muscle Mass

Owing to low cardiac output and significant reduction in physical activity, patients at risk of severe heart attack have tendency to lose muscle weight over time.

Gastrointestinal Symptoms

Patients lose appetite and feel full even after eating small amounts. They may also have abdominal pain.

Pulmonary Edema

Pulmonary edema, a condition characterised by fluid buildup in the lungs. All of the symptoms may become severe owing to this. The following may happen because of pulmonary edema:
•    Shortness of breath, accompanied by cough that produces a pinkish froth.
•    A bubbling sensation in the lungs and feeling of drowning.
•    Skin turning clammy and pale, nearly blue in some cases.

Abnormal Heart Rhythms

There could be many episodes of abnormally fast or slow heart rate.

Central Sleep Apnoea

The brain of a patient may fail to signal the muscles to breathe during sleep. If heart failure advances, the apnoea may be so acute that one is unable to breathe and awaken from sleep in panic.