high altitude pulmonary oedema

A serious, often fatal condition in which fluid accumulates in the lungs of some individuals who ascend heights exceeding 2400 metres (7874 feet). See also altitude.

Accumulation of fluid in the lungs at high altitude. It occurs most frequently in those who ascend rapidly to altitudes above 2700 m. The fluid interferes with ventilation, and results in shortness of breath and fatigue. Oxygen transport to the brain is impaired, leading to mental confusion and loss of consciousness. The condition is potentially fatal. Its precise cause is unknown. HAPE is treated by administering supplemental oxygen and returning the patient to a lower altitude. See also Gamow bag.