. Friday, September 26, 2008
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Until recently, altitude sickness was something of a rarity. People didn’t zip to Aspen for weekend trips. And serious climbers only ascended as fast as their feet would take them.

Things changed with modern transportation. Today’s hikers, skiers and climbers can shoot from sea level mountaintop in no time. They don’t have time to adjust to changes in altitude, a process called acclimatization, says Benjamin D. Levine, M.D., an assistant professor of medicine at the University of Texas Southwestern Medical Center in Dallas and director of the Presbyterian Institute for Exercise and Environmental Medicine. “Anyone can get altitude sickness if they go up to high enough altitudes fast enough,” he says.

High Altitude, Low Oxygen

Altitude sickness is caused by the low level of oxygen available at high altitudes. Nearly 700 years ago, the explorer Marco Polo noted that high mountain air could be “so unwholesome and pestilential that it is death to any foreigner.” The air at your favorite ski resort isn’t so hazardous, of course. Indeed, says Dr. Levine, the vast majority of people who get sick at high altitudes will have only mild symptoms––headache, fatigue, nausea and loss of appetite.

Altitude sickness generally sets in within 12 to 48 hours of arrival at your high-altitude destination, gets worse during the night, then gradually improves as your body gets accustomed to the diminished oxygen stores. “For skiers going to Colorado, 25 or 30 percent of them will have some symptoms of altitude sickness, and some will lose skiing or vacation time because of it,” Dr. Levine says. The risk is proportional to the altitude achieved. In studies in the Swiss Alps, researches found that 13 percent of the people who climbed to 10,000 feet experienced altitude sickness. At 15,000 feet, the number jumped to 53 percent.

While the symptoms are usually mild, altitude sickness will occasionally cause disorientation, hallucinations and edema––the accumulation of fluid in the lungs or brain. Untreated, this edema can be fatal, Dr. Levine says. So don’t take chances your first day on the slopes. You can protect yourself––if you follow the rules.

The Lowdown on Going High

To prevent altitude sickness, Dr. Levine says, you need to pace yourself. For starters:

Climb high, sleep low. The severity of altitude sickness largely depends upon the altitude at which you sleep. “If you can, spend your first night at lower altitudes––say, below 7,000 feet,” Dr. Levine says. “For example, someone going to ski in Keystone, Colorado (9,000 feet), could spend the first night in Denver or Colorado Springs (5,000 feet).”

Ascend slowly. Above 8,000 to 10,000 feet, doctors say, you should allow one acclimatization day for each 2,000 feet you ascend. Indeed, going slowly is such an integral part of climbing that experienced mountaineers may take weeks to make a long ascent.

Pace yourself. Doing hard exercise soon after arriving at altitude often triggers symptoms. For example, people who ski hard their first day, then stay up dancing all night, are asking for trouble, Dr Levine says. It’s better to take it easy the first day, get a good night’s sleep, then conquer the mountain the second or third day.

Bag the salt. Even mild cases of altitude sickness seem to be accompanied by slight edema, resulting in the swelling of tissues. You can fight edema by eating salt and by drinking lots of water.

Can the beer. The sleeping pills, too. “Alcohol and sedatives, by slowing breathing, can aggravate the effects of altitude,” says Dr. Levine.

Fill up on carbs. Unlike high-fat, high-protein foods, carbohydrates such as rice and potatoes help your metabolism work more efficiently, which can make it easier to get more oxygen at high altitudes.

Go down. This is the one sure cure for altitude sickness. Once people descend a few thousand feet, Dr. Levine says, they usually start feeling better within minutes or hours.

A tip on Drugs

To prevent altitude sickness, prescription drugs such as acetazolamide and nifedipine work quite well, but they are not routinely recommended unless an individual has a previous history of altitude sickness.

For treatment, perhaps the most powerful drug is a steroid called dexamethasone, which can quickly relieve most symptoms. Because of possible side effects, however––ranging from high blood sugar disorientation–dexamethasone is recommended only for emergencies, says Dr. Levine.


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