Swiss perspectives in 10 languages

Swiss mount altitude sickness study in Himalayas

The medical researchers will set up their base on the towering Muztagh Ata peak.

Swiss mountain researchers are planning an expedition to the Himalayas to carry out a new study of altitude sickness.

The team of scientists will accompany a group of volunteers to the isolated Kunlun Shan range near the border between China and Tajikistan.

The main goal of the expedition, which will take place next year, is to improve understanding of how the body fights against high altitude pulmonary edema (HAPE), a condition that can occur when a person ascends a mountain too quickly.

HAPE causes fluid retention in the lungs, with victims suffering from shortness of breath, extreme fatigue and coughing up blood. Unconsciousness, coma and even death can occur, if the symptoms are not dealt with promptly.

A similar project took place last year, with volunteers trekking to Switzerland’s highest mountain hut in the Monte Rosa range for tests, 4,554 metres above sea level.

This time around, 36 climbers, along with ten guides and four doctors, will head even higher, to western China’s Muztagh Ata, which lies well above 7,000 metres.

“We believe there will be very different results from the ones we already got in the Alps,” said Tobias Merz, one of the expedition’s leaders and doctors.

“The air pressure and the blood oxygen saturation level are so low at that altitude that we should get data that cannot be recorded at lower down.”

Easy climb

The team of doctors will also study how the lack of oxygen at high altitude affects the brain. The researchers plan to focus on the climbers’ breathing and heart rates.

Tests will be carried out on the climbers at different altitudes as they make their way up to 7,000m.

“We want them to acclimatise gradually at different altitudes because sending anybody up straight away might kill them,” Merz told swissinfo.

According to Merz, the mountain itself is not particularly hard to climb, and in an emergency, climbers can even ski down its slopes. The biggest difficulty lies in the altitude itself.

“At 7,000 metres, doing anything is extremely hard,” he explained. “The tests will also require big efforts from the researchers.”

The team’s testing equipment could also be affected, as it has never been used at such high altitude.

Guinea pigs

The expedition is still 11 months away, but the medical team has begun its search for volunteers who are prepared to spend a month on the slopes of the Chinese mountain.

“They need some experience as climbers, but they don’t need to be experts,” said Merz. “They should also be in very good physical condition because it still involves a major effort to get up there.”

But the volunteers will not just need to be fit; some of them must also have been affected by altitude sickness in the past.

“We want to compare the reactions of people who are prone to HAPE with those who aren’t,” Merz told swissinfo.

They will have to submit to a series of essentially painless experiments during their stay on Muztagh Ata, as well as before and after in Zurich.

And while a month on a mountain might seem a long time, Merz says the expedition will be working to a tight schedule.

“Everything takes longer at that altitude,” he said. “It won’t be like working in a laboratory where everything is comfortable and you have a coffee machine at hand.”

swissinfo, Scott Capper

Peak: Muztagh Ata.
Altitude: 7,546 metres.
Location: Kunlun Shan range, Xinjiang, China.
The peak is only 24 kilometres from the China-Tajikistan border.
It towers above the Karakoram Highway, the main road leading to Pakistan.

A team of 36 climbers, with 12 guides and doctors, is planning to climb China’s Muztagh Ata peak in 2005 to study the effects of altitude sickness.

The mountain was chosen because of its height and the ease with which higher altitudes can be reached.

The researchers will focus on HAPE, the effects of a lack of oxygen on the brain, breathing and heart rates.

Deeply Read

Most Discussed

In compliance with the JTI standards

More: SWI certified by the Journalism Trust Initiative

You can find an overview of ongoing debates with our journalists here . Please join us!

If you want to start a conversation about a topic raised in this article or want to report factual errors, email us at

SWI - a branch of Swiss Broadcasting Corporation SRG SSR

SWI - a branch of Swiss Broadcasting Corporation SRG SSR