High-Altitude Sickness
General Information

Patients planning travel to altitudes above 6,000 to 8,000 feet above sea level may be susceptible to high-altitude illness. Vulnerability to these conditions is not affected by fitness or physical training. Previous experience in high-altitude conditions seems to be the only reliable predictor of susceptibility, and even that is not completely reliable. The three most common types of high-altitude illness are Acute Mountain Sickness, High-Altitude Cerebral Edema, and High-Altitude Pulmonary Edema.

Acute Mountain Sickness (AMS) results from rapid ascent to high altitude in patients who are not acclimatized to conditions at that altitude. It is common in mountain climbers, but also people flying or taking other rapid transportation (e.g., trains, cars or buses) to locations at altitudes above 8,000 feet. The altitude at which the patient sleeps is a critical factor, with incidence increasing sharply above a sleeping altitude of 9,000 feet.

• At onset, AMS feels exactly like a hangover. Symptoms include throbbing headache, nausea, vomiting, frequent awakening during sleep, dizziness or lightheadedness, and fatigue. Ascent to higher altitudes should be halted until acclimatization occurs.

• Generally treatment involves alleviation of symptoms with oxygen during sleep, aspirin for headache, and anti-nausea medication for nausea and vomiting. Symptoms should be monitored; if they do not improve or if they worsen, the patient should descend to a lower altitude.

• AMS may increase in severity, causing swelling in the lungs or brain. These conditions, High-Altitude Pulmonary Edema (HAPE) and High-Altitude Cerebral Edema (HACE), require immediate descent to lower altitudes and immediate medical attention.

• Symptoms of HAPE and HACE include difficulty breathing, increased heartrate, fatigue, weakness, low grade fever, cyanosis or pallor, confusion, drowsiness, loss of coordination, nausea and vomiting, and, rarely, hallucinations and seizures. Treatment can include supplemental oxygen, steroids, and hyperbaric treatments.

• Other disorders are experienced at high altitudes, including sleep disturbances, swelling of the extremities, sore throat or bronchitis, retinal hemorrhages (common above 15,000 feet), migraine, stroke and ultraviolet keratitis ("snowblindness"). These can be experienced concurrent with or independently of AMS, HAPE and HACE.

Centers for Disease Control and Prevention Information on High-Altitude Sickness

Travelers Printable Checklist (PDF)
© Copyright 2016 Joseph Mulvehill, M.D. All Rights Reserved
860 Fifth AvenueSuite 1H New York, NY 10065
ph (212) 737-3136
fax (212) 737-3481