Have you ever had a nasty hangover? That’s a pretty close approximation to altitude sickness, says David Shlim, M.D., a Wyoming-based expert who headed a travel medicine clinic in Kathmandu for 15 years. “If you ascend slowly, you usually don’t notice,” he explains. But when you go up faster than your body can adjust, nausea, dizziness, headache, and fatigue occur. These are signs of acute mountain sickness, or AMS, the most common form of altitude illness. AMS can lead to more serious, even life-threatening conditions known as high-altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE), when fluid accumulates in the lungs or the brain cavity.
AMS can occur at moderate altitudes like Denver’s (5,280 feet), but it’s more common during travel to places such as Cuzco, Peru (11,000 feet), or Lhasa, Tibet (12,000 feet). Mount Kilimanjaro, whose peak is 19,340 feet, has a high incidence of altitude sickness. “There are no villages to hang out in on the way up, so people ascend too fast,” Shlim says. “You want to take the longest trip to the summit, not the shortest.” And living somewhere like Colorado doesn’t protect you. Susceptibility varies by individual and is unrelated to age or fitness. “It’s a myth that once you get it, it’s easier to get in the future,” says Shlim. “All it means is that you’re susceptible and you’ll have to adjust.”
That might require taking the drug acetazolamide, which is sold under the name Diamox. “It acidifies the blood slightly,” explains Shlim. “When your brain senses that, it causes you to increase your respiration, to blow off carbon dioxide. People have tried breathing deeper and faster to adjust, but it just doesn’t work.”
There are no absolute rules regarding altitude sickness prevention, only guidelines. One shouldn’t attempt more than 1,000 feet per day after 10,000 feet. And Shlim’s rule is: If you don’t feel well, it’s altitude sickness until proven otherwise. Generally, it’s not necessary to descend immediately unless your condition worsens. Supplemental oxygen can help reduce symptoms, but a day or so of rest is still essential. “If you go higher before your symptoms go away, it’s 100 percent certain they’ll get worse,” says Shlim. “And if you carry on, it can be fatal.”
“While hiking an ancient Incan trail near Machu Picchu, I slid on some wet ground, my right foot lodged between two rocks, and crack. My foot just hung there at a ninety-degree angle to my leg. Luckily my companion had a cell phone. A local doctor clambered up to give me a shot for the pain, and hotel workers made a splint and a stretcher out of branches and carried me a half mile down the mountain—I’m sure they heard me screaming all over Peru. X-rays at a clinic in Cuzco revealed a major break above the ankle. Fortunately, I’d signed up for an emergency evacuation plan (the company is a client of my PR firm), and they sent a Learjet staffed with two nurses. There was even a choice of movies—Intolerable Cruelty would have been fitting.” —Geoffrey Weill, president of Geoffrey Weill Associates