The hyperventilation syndrome is very common—an incidence of as much as 10% in the office practice of a primary care physician. The acute form of hyperventilation is easily recognized and is commonly diagnosed in the emergency room and other outpatient settings. With the dramatic findings of overt anxiety, transitory bouts of hyperpnea, carpopedal spasm, and other symptoms of tetany, it is seldom misdiagnosed. However, chronic hyperventilation, the form represented by 99% of patients with the syndrome, can manifest itself by bizarre and often apparently unrelated symptoms that may affect any part of the body and any organ system.1 The pathophysiological effect may be functional cardiac or gastrointestinal disease, chronic nervous exhaustion, atypical fibromyositis or other myalgias, neurocirculatory asthenia, or various other disorders.
Even after the physician has diagnosed hyperventilation syndrome and confirmed it with negative laboratory data, he may find it difficult to explain to the patient how anxiety