Dangerous heights

When the well-known Norwegian skier Vegard Ulvang climbed Mount Elbrus in 1992, he barely made it to the summit. Europe's highest peak almost defeated the highly trained athlete who had won Olympic and World Cup gold medals. Ulvang did manage to reach the top, but other experienced mountain climbers, such as Arne Næss, Jr. and Stein P. Aasheim, did not make it. They had to turn back.

Less oxygen to breathe

"People notice altitude sickness beginning at about 2,500 metres above sea level," explains Are Løset of the Norwegian University of Science and Technology (NTNU) in Trondheim. Løset conducts research on what happens to the body at high altitudes, and he knows that the higher the altitude, the lower the oxygen pressure in the atmosphere. "There is simply less oxygen to breathe," he explains.

Løset has been on Mount Aconcagua in South America twice. At an altitude of almost 7,000 meters, he and other researchers used extensive medical equipment to study what happens to the body as oxygen pressure decreases.

Is it genetic?

It is a mystery why the two Norwegian journalists who covered Ulvang's trip to Mount Elbrus were able to reach the summit. Level of fitness or age did not seem to play a role in determining who became sick.

Researchers from NTNU at an expedition to Aconcagoa in South America. PHOTO: NTNU

"We cannot predict who will experience problems at high altitudes," explains Løset. Therefore, researchers at NTNU want to develop a simple test that can be used to find out who will experience altitude sickness. Among other things, they are looking for a particular gene. Researchers believe that people with this gene are more likely to react to high altitudes.

From uncomfortable to life-threatening

"There are three types of altitude sickness," the researcher explains. "One type is acute altitude sickness. Most people who climb at high altitudes experience acute altitude sickness at some time. They become nauseous, get a headache and feel very tired. These symptoms usually disappear if the body is given time to adjust to the altitude. It is important to take it easy and not try to climb up too fast."

If the symptoms worsen, it may be a sign of more serious altitude sickness. "Then there is just one thing to do: climb down to a lower altitude as fast as possible," says Løset. The other two types of altitude sickness may be life-threatening. Water may fill the lungs, a condition known as pulmonary oedema, or the brain may begin to swell, which is referred to as cerebral oedema. People suffering from cerebral oedema are totally reliant on help since they are often confused and cannot walk. If they do not get down to a lower altitude and receive treatment in time, their lives may be in danger.

Useful for others

If researchers in Trondheim are able to predict who is most likely to experience altitude sickness, there could be fewer fatal accidents in the mountains. But research on high altitudes is also useful for people who are not mountaineers.

"Astronauts, divers, new-born babies and people with heart and lung diseases may also be prone to too little oxygen in the body," explains Løset.

Published in 'Nysgjerrigper' no. 1/08

Translated by Connie Stultz