Chronic mountain sickness at an elevation of 2,000 meters.

A resident living at Lake Tahoe, Calif, at an elevation of 2,000 meters, had fatigue, edema, and erythrocythemia. Hematocrit was 63 percent, and arterial blood gas values revealed hypoxemia and respiratory acidosis. Results of pulmonary function tests, sleep study, and thyroid function all were normal. Erythrocytosis, cor pulmonale, and respiratory acidosis resolved after the patient moved to sea level. This patient suffered from chronic mountain sickness. Her symptoms resolved with relief of hypoxia.