ACCLIMATIZE BEFORE MAKING MOUNTAIN CLIMBS
One writer learned about altitude sickness the hard way on Himalayan excursion
When I told friends I was going to Tibet last spring, almost everyone asked, “What are you doing to prevent altitude sickness?”
Not nearly enough, it turned out, given the headaches, insomnia and occasional wooziness I experienced during four days in Lhasa. The Tibetan capital rises from the Himalayan Plateau to 3,651 metres above sea level — more than twice the elevation of Denver.
Already badly jet-lagged after deplaning in Lhasa, I suddenly faced a third less breathable oxygen than in the low-lying cities I’d just left: Beijing, Los Angeles and Washington, D.C., where I live. Even our not-so-rigorous Tibetan sojourn — which involved some walking, multiple bus rides and the occasional long or steep climb to a palace or monastery — played havoc with my head, heart and lungs.
Road Scholar, our Boston-based tour operator, had advised us to increase our pre-trip aerobic exercise and deep breathing for several months to improve stamina and insisted that we consult doctors to learn about altitude sickness risks and remedies. But because we had flown straight from sea level in Beijing to more than three kilometres up in Lhasa without giving our bodies time to acclimate, some of us were shocked by how awful we felt.
What is altitude sickness? Put simply, it’s the body’s reaction to decreased oxygen levels. We lose three per cent of inhaled oxygen molecules for every 305 vertical metres travelled, according to altitude researchers. To compensate, travellers inhale more frequently and can feel out of breath. With additional symptoms including headache, nausea, vomiting, dizziness and fatigue, altitude sickness can mimic a really bad hangover.
There are three types of altitude-induced illness. Fortunately, only the mildest type struck some in our 11-member group: acute mountain sickness (AMS), commonly called altitude sickness. Two related and potentially fatal ailments can occur when lower air pressure and higher altitudes cause capillaries to leak: high altitude pulmonary edema (HAPE), a buildup of fluids in the lungs; and high altitude cerebral edema (HACE), a buildup of fluid in the brain. In extreme cases, AMS can become HAPE or HACE or the illnesses can develop on their own without being preceded by the milder one.
Regardless of age, sex, body type and fitness level, one or more of these maladies can hit anyone at any high-altitude location — including Antarctica — according to medical experts. Two years ago, former astronaut Buzz Aldrin, then a hale 86, had to be airlifted from an elevation of 2,835 metres in the South Pole. Congested lungs kept him in a New Zealand hospital for a week.
If you’re planning a high-altitude adventure, a bit of prevention could save your vacation — if not your life. Discomfort can set in as low as 914 metres for those with lung disease; for others, problems won’t appear until around 2,438 metres.
For context, Mount Everest, the world’s tallest peak, rises to 8,848 metres; Alaska’s Denali, the highest peak in the United States, hits 6,190 metres; and Mount Kilimanjaro in Tanzania stops at 5,895 metres.
The best strategy, as Road Scholar noted, is to acclimate the body at lower elevations before heading skyward. Another way to sidestep AMS is to “climb up and sleep down” at less strenuous lower altitudes. This means heading to higher ground from your hotel or base camp, but spending the night at the starting point or another less-elevated site where there is greater oxygen density.
Many high-altitude seekers rely on Diamox (a brand of acetazolamide), a popular prescription drug that “stimulates breathing and raises your oxygen level,” said Peter Hackett, an emergency medicine physician, altitude sickness expert and experienced mountaineer. Yes, you’ll urinate more often, carbonated drinks may taste odd and your toes and fingers will tingle, he said, but those are temporary and harmless side effects. While the body usually needs two to four days to adjust to high altitudes, “Diamox does the same thing in about eight hours, speeding the natural process,” said Hackett, noting that the drug works for 85 to 90 per cent of people.
There are also favourite local remedies: yak butter tea in the Himalayas, which our Tibetan and Nepali guides swore by, and coca leaf tea, containing minuscule traces of the alkaline known as cocaine — the highly processed drug that shares its name uses the leaves — and widely served in the Andean regions of South America, which several of my fellow travellers had savoured in Cusco, Peru (3,399 metres). Alas, the tea is banned in the United States.
Many hotels in mountainous areas pump extra oxygen into guest rooms, especially overnight; others provide small personal oxygen canisters or portable units in rooms. I used a machine the size of a small radiator in Lhasa. It cost $5 per hour with a sterile nose hose included. During those 60 minutes, I felt marginally better, although the headache roared back afterward because the body can’t store supplemental oxygen.
I could have kicked myself during our time in Lhasa for stupidly, inexplicably choosing not to take the Diamox I’d brought along.
Sometimes, the cure can be mistaken for the ailment. Conventional wisdom urges highaltitude travellers to temporarily avoid caffeine, a diuretic that hastens dehydration and constricts capillaries.
Consequently, what seems like altitude sickness can, in fact, be caffeine withdrawal, which struck one group member who usually downs eight to 10 cups of black tea a day.