High-Altitude Illnesses: Physiology, Risk Factors, Prevention, and Treatment

• Type of Material: Article
• Authors: Andrew T Taylor Jr., Emory University
• Language: English
• Date: 2011-01
• Publisher: Rambam Health Care Campus
• Publication Version: Final Published Version
• Copyright Statement: © 2011 Andrew T. Taylor.
• License: Creative Commons Attribution 3.0 Unported
• Final Published Version (URL): http://www.rmmj.org.il/userimages/41/1/PublishFiles/44Article.pdf
• Title of Journal or Parent Work: Rambam Maimonides Medical Journal
• ISSN: 2076-9172
• Volume: 2
• Issue: 1
• Start Page: e0022
• End Page: e0022
• Keywords: acetazolamide; high-altitude pulmonary edema; Acute mountain sickness; high-altitude cerebral edema
• Research Categories: Health Sciences, Public Health; Health Sciences, Radiology; Health Sciences, Mental Health

Abstract

High-altitude illnesses encompass the pulmonary and cerebral syndromes that occur in non-acclimatized individuals after rapid ascent to high altitude. The most common syndrome is acute mountain sickness (AMS) which usually begins within a few hours of ascent and typically consists of headache variably accompanied by loss of appetite, nausea, vomiting, disturbed sleep, fatigue, and dizziness. With millions of travelers journeying to high altitudes every year and sleeping above 2,500 m, acute mountain sickness is a wide-spread clinical condition. Risk factors include home elevation, maximum altitude, sleeping altitude, rate of ascent, latitude, age, gender, physical condition, intensity of exercise, pre-acclimatization, genetic make-up, and pre-existing diseases. At higher altitudes, sleep disturbances may become more profound, mental performance is impaired, and weight loss may occur. If ascent is rapid, acetazolamide can reduce the risk of developing AMS, although a number of high-altitude travelers taking acetazolamide will still develop symptoms. Ibuprofen can be effective for headache. Symptoms can be rapidly relieved by descent, and descent is mandatory, if at all possible, for the management of the potentially fatal syndromes of high-altitude pulmonary and cerebral edema. The purpose of this review is to combine a discussion of specific risk factors, prevention, and treatment options with a summary of the basic physiologic responses to the hypoxia of altitude to provide a context for managing high-altitude illnesses and advising the non-acclimatized high-altitude traveler.