Health Watch -- Obesity and Altitude

Health Watch is a Public Service of the Office of News and Publications and is intended to provide general information only and should not replace the advice of a medical professional. You should contact your physician if you have questions about any of these topics.

Some people may need to be particularly careful when ascending the heights.

The human body may have difficulty adapting to higher altitudes. Doctors have a name for this: acute mountain sickness, or A-M-S. It's caused by rapid ascent to altitudes higher than about 8,000 feet above sea level. Symptoms include headache, nausea and vomiting, fatigue, weakness, dizziness and sleep disorders.

Now researchers at UT Southwestern Medical Center at Dallas have found that obese people have an even higher risk of developing A-M-S. In a study conducted at the Institute for Exercise and Environmental Medicine, a joint project between UT Southwestern and Presbyterian Hospital of Dallas, the researchers compared responses of obese people and non-obese people to changes in air pressure. They created conditions like those found in high altitudes using a decompression chamber.

Study participants recorded their symptoms at sea-level conditions and then again in high-altitude conditions. More than 70 percent of the obese participants reported mountain-sickness symptoms, while only 40 percent of the non-obese participants showed symptoms. The obese participants also had more severe symptoms.

Dr. Tony Babb, the UT Southwestern researcher who led the study, says obese people planning a trip to the mountains need to take extra precautions. If possible, plan a more gradual ascent to altitude. Don't engage in strenuous activity until you're acclimated. And you may want to talk to your doctor about prescription medication you can take to ease altitude symptoms.