Shortness of Breath

SHORTNESS OF BREATH

Shortness of breath (SOB, dyspnea) is defined as an abnormal uncomfortable awareness of breathing. It is best quantified by the amount of physical activity it takes to bring it on (e.g. walking a block). Whether or not it is related to body position is also important. For example, orthopnea refers to SOB while lying supine. It may indicate heart disease. Healthy adults take about fourteen 600 ml. breaths each minute. Persons who are severely SOB breathe much more rapidly and deeply.

Major Causes

SOB may be caused by a wide number of disorders which affect the lungs, chest wall, respiratory muscles, heart and nervous system. Any obstruction to the normal flow of air from the mouth and nose to the tiny air sacs in the lungs can produce SOB. Back and ribcage deformities, as well as paralysis or weakness of the respiratory muscles, can upset the normal mechanics of inspiration and expiration. Diseases that damage the oxygen- absorbing membranes and small blood vessels in the lungs also cause this symptom. Heart and blood disorders are commonly implicated. Persons with kidney failure or diabetic coma may experience SOB as they hyperventilate to rid their bloodstream of excess acid. Hyperventilation associated with fear, pain or anxiety is a relatively benign disorder. The common disorders that cause of SOB are asthma, blood clot in the lungs, bronchitis, heart failure, emphysema, collapsed lung, pneumonia, work-related diseases such black lung and asbestosis, and anemia.

Evaluation

SOB is often a symptom of serious disease of the heart or lungs. For this reason, it requires thorough evaluation by a physician. A history of smoking, cough, chest pain, fever, heart disease or chest injury may point towards the diagnosis. When the symptoms are severe or new in onset, a complete examination with bloodwork, chest X-ray and electrocardiogram (EKG) is usually indicated. Specialized breathing tests and measurement of the blood oxygen concentration may be necessary.

Treatment

General measures such as rest, avoidance of tobacco and supplemental oxygen administration are employed. Mechanical ventilation (respirator) is required for life-threatening situations. The use of antibiotics, heart and breathing medications or surgery depends upon the specific cause.