Link Between Altitude Illness and Dehydration

Doctors at Sinai Hospital have found that a person's risk of becoming ill when exposed to high altitude (more than 4,300 meters) increases as the rate of dehydration and the body's inability to adapt to environmental stressors increases. The study is published in the September 2002 issue of Aviation, Space, and Environmental Medicine. The study was performed in conjunction with the Nepal International Clinic and the Himalayan Rescue Association.

Illness at high altitude, also known as Acute Mountain Sickness (AMS), has been a problem for hundreds of years. It remains unclear, however, exactly why some people are less affected, and others can become seriously ill. In some cases, this illness can result in death.

This study examined a population of people undertaking an ancient Hindu pilgrimage to a sacred high altitude lake in the Langtang Region of the Nepal Himalayas. Several tests were performed to measure different fluid levels in the body and to monitor how the kidneys respond to stress. Healthy persons were compared to those who developed AMS as well as those with excessively low oxygen levels.

"We found that certain problems can exacerbate this situation, ultimately contributing to the development of this illness," said Tom Cumbo, M.D., lead author and chief medical resident, Sinai Hospital/Johns Hopkins University Residency Program in Internal Medicine. "Although preliminary, these data suggest that dehydrated individuals may have greater difficulty adjusting to metabolic changes, including acid-base metabolism, resulting from high altitude ascent. These factors appear to significantly increase a person's chance of suffering from AMS."

Using the information from this and further studies, researchers hope to develop a system whereby clinicians and religious officials can identify those more susceptible to the disease, ultimately reducing suffering and death.