Dyspnea

Shortness of breath
Synonyms	dyspnea, dyspnoea, shortness of breath (SOB), breathlessness
Classification and external resources
Specialty	Pulmonology
ICD-10	R06.0
ICD-9-CM	786.09
DiseasesDB	15892
MedlinePlus	003075
Patient UK	Shortness of breath Shortness of breath
MeSH	D004417
[]

Shortness of breath, also known as dyspnea, is a feeling like one cannot 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 the distinct sensations, the degree of distress involved, and its burden or impact on activities of daily living. Distinct sensations include effort/work, chest tightness, and air hunger (the feeling of not enough oxygen).

Dyspnea is a normal symptom of heavy exertion but becomes pathological if it occurs in unexpected situations or 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 causes, such as panic disorder and anxiety. Treatment typically depends on the underlying cause.

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 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, other systems such as neurological,musculoskeletal, endocrine, hematologic, and psychiatric may be the cause.DiagnosisPro, an online medical expert system, listed 497 distinct causes in October 2010. The most common cardiovascular causes are acute myocardial infarction and congestive heart failure while common pulmonary causes include chronic obstructive pulmonary disease, asthma, pneumothorax, pulmonary edema and pneumonia. On a pathophysiological basis the causes can be divided into: (1) an increased awareness of normal breathing such as during an anxiety attack, (2) an increase in the work of breathing and (3) an abnormality in the ventilatory system.

...
Wikipedia