Shortness of breath

Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity", and recommends evaluating dyspnea by assessing the intensity of its distinct sensations, the degree of distress and discomfort involved, and its burden or impact on the patient's activities of daily living. Distinct sensations include effort/work to breathe, chest tightness or pain, and "air hunger" (the feeling of not enough oxygen). The tripod position is often assumed to be a sign. Dyspnea is a normal symptom of heavy physical exertion but becomes pathological if it occurs in unexpected situations, when resting or during light exertion. In 85% of cases it is due to asthma, pneumonia, cardiac ischemia, interstitial lung disease, congestive heart failure, chronic obstructive pulmonary disease, or psychogenic causes, such as panic disorder and anxiety. The best treatment to relieve or even remove shortness of breath typically depends on the underlying cause. Dyspnea, in medical terms, is "shortness of breath". The American Thoracic Society defines dyspnea as: "A subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity." Other definitions also describe it as "difficulty in breathing", "disordered or inadequate breathing", "uncomfortable awareness of breathing", and as the experience of "breathlessness" (which may be either acute or chronic). While shortness of breath is generally caused by disorders of the cardiac or respiratory system, others such as the neurological, musculoskeletal, endocrine, hematologic, and psychiatric systems may be the cause. DiagnosisPro, an online medical expert system, listed 497 distinct causes in October 2010.