The medical term for shortness of breath is dyspnea. It is often described as a hunger for air. It can be the symptom of an underlying problem, such as lung disease or anemia, or simply the normal result of exertion, such as vigorous exercise.

There are certain types of dyspnea that occur at night and are usually related to heart failure. A person may suddenly wake up very short of breath and have to sit up in bed. A window may have to be opened for fresh air. After sitting upright for a while, the person is finally able to resume a normal breathing pattern. This is called paroxysmal nocturnal dyspnea. Some people must have their head and chest elevated to avoid shortness of breath while sleeping. Some can only sleep sitting up in a chair. This type of dyspnea is called orthopnea.

Dyspnea can be caused by many conditions. In patients with defective heart valves, blood may leak backwards into the lungs. This excess fluid in the lungs causes the lung tissues to swell, resulting in shortness of breath. Other patients may suffer from heart muscle problems, called cardiomyopathy. This can cause the blood to back up into the heart and lungs, also resulting in dyspnea. Shortness of breath associated with heart disease can cause coughing and wheezing, although coughing and wheezing are frequently due to other problems as well, such as lung disease. Smokers often suffer from both heart and lung disease.

Of the most severe forms of heart failure, one type of advanced shortness of breath is called pulmonary edema. In this condition, the lungs literally fill with fluid. Patients are treated with powerful diuretics, which eliminate some excess fluid through the kidneys. They may also be given drugs to help the heart contract more forcefully. In most cases, pulmonary edema can be treated with medicines, but it can be so severe the patient may have to be connected to a mechanical ventilator. If a ventilator is needed, most patients can be removed from it in a day or two. In other patients, depending upon the underlying cause, further intervention may be necessary.

Patients who are short of breath tend to breathe more rapidly. This rapid breathing is known as tachypnea. It can be associated with heart failure but isn't always. Hyperventilation is a somewhat different type of rapid breathing. If you're hyperventilating, it feels as if you can't catch your breath, and you breathe rapidly. The cause may actually be an anxiety attack unrelated to heart disease. Often a physician is needed to distinguish between tachypnea and hyperventilation.