An experienced Sherpa guide who has scaled Mount Everest at least 10 times has died at the mountain's base camp, becoming the first fatality in this year's spring climbing season.

Karsang Namgyal, 40, died Wednesday from altitude sickness, expedition organizer Dambar Parajuli said. The base camp is located at 5,300 meters (17,380 feet).

Parajuli said Namgyal did not appear to be sick or have any physical problems before Wednesday, when he complained of uneasiness and later died.

Namgyal was an experienced mountain guide who scaled Everest at least 10 times and climbed several other high peaks in Nepal, Parajuli said. An autopsy was scheduled to be done Thursday in Nepal's capital, Katmandu.

Altitude sickness is a leading cause of death for climbers and trekkers on the high Himalayan peaks.

Namgyal is the son of Ang Rita, a legendary climber who was the first to scale Everest 10 times before health problems forced him to retire.

Hundreds of climbers and their guides are currently camped at Everest's base camp preparing to scale the world's highest mountain.

Climbers generally try to scale Everest in May, when weather conditions have usually improved just enough to enable them to attempt to reach the 8,850-meter (29,035-foot) peak.