Altitude Sickness Kills Fourth Climber on Mount Everest In Four Days; What Are Its Causes and Symptoms?

Within four days, four people have died on Mount Everest, while two people have been reported missing.

CNN reported that as per Nepal's tourism department, there has been at least one death associated with climbing the world's highest peak since 1990. Between 1922 and 2010, 219 lives were lost trying to conquer the Everest.

The recent deaths, however, have been so close to each other that hikers now starting their descent have been rattled.

The climb to Mount Everest's summit at 29,029 feet was stopped after the deadly Nepal earthquake in 2015. Climbing season was also canceled in 2014 when an avalanche killed 16 Nepalese guides. The recent hikes this year marked the first time the summit was reached after two years.

On Thursday, 25-year-old Phurba Sherpa fell to his death. The crew member was working to fix a route around 150 meters near the summit when he fell. He is a member of the Sherpa people, an ethnic group from Nepal who have lived in the Himalayas for generations. They have served as guides for foreigners attempting to scale the Everest.

The following night, Eric Arnold of Netherlands died after a successful summit. The 36-year-old triathlete was suspected to have passed away due to a heart attack.

Meanwhile, altitude sickness is seen as the reason for the deaths of an Australian woman and an Indian man during the weekend. Finance professor Maria Strydom, 34, died before she could descend to Camp III on Saturday. The following day, Subash Paul, 44, passed away at Base Camp II due to the same sickness.

What is altitude sickness?

Also called acute mountain sickness, altitude sickness happens when people have difficulty adapting to low oxygen levels at high altitudes, such as at Mount Everest, as per BBC.

The Sydney Morning Herald reported that when ascending to high altitudes at a fast pace, the body does not have time to adjust to the changing conditions, and in turn, suffers hypobaric hypoxia, in which oxygen fails to reach the tissues.

Mild cases result in nausea or dizziness, headaches, loss of coordination and weakness. But there is a risk of potentially fatal fluid build-up in the brain and lungs, and can result in comatose or death.

It is not an unusual sickness to have while climbing the world's highest peak.

Those who suffer from altitude sickness are advised to immediately go to a lower altitude and take in fluids and bottled oxygen. There are also drugs to reduce the symptoms but these may have side effects.