High-altitude exposure and its effects on special populations

Altitude illness is a spectrum of conditions that affect the majority of travelers to high elevations (>8200 ft [2500 m]). The rapid decrease in arterial oxygen saturation with increasing altitude is the physiologic basis for this group of disorders. Many travelers to high altitudes will experience symptoms of acute mountain sickness including headache, fatigue, dyspnea, and dizziness. Prolonged exposure can result in more serious pulmonary, central nervous system, and circulatory disorders. Core treatments for most altitude-related illnesses include descent, rest, medications, and supportive care. Children and travelers with chronic diseases are more susceptible to altitude illness compared with the general population. Pregnant women residing at high altitudes are at increased risk for pregnancy-induced hypertension, preeclampsia, and low-birth-weight infants. Early recognition and treatment of altitude illness can prevent life-threatening situations. Primary care physicians should counsel patients traveling to high altitudes about altitude illness and discuss medications available for mountain sickness prophylaxis.