A Melbourne university lecturer has died of altitude sickness while descending Mount Everest and there are concerns for her husband trekking with her.
Dr Maria Strydom, a finance lecturer at Monash University, fell ill and died on Saturday afternoon.
"After reaching the summit yesterday she said she was feeling very weak and suffering from a loss of energy ... signs of altitude sickness," Seven Summit Treks board director Pasang Phurba Sherpa said.
An experienced climber, Strydom, 34, was travelling with her husband Robert Gropel on a seven-week expedition.
The Department of Foreign Affairs and Trade says it is providing consular assistance to her family and "to an injured Australian man accompanying the woman".
Strydom's mother Maritha Strydom confirmed her death on Facebook, sharing a news story under the comment: "My beautiful girl".
"Praying for Rob's safety," she posted.
Monash University said in a statement it was "deeply saddened by the tragic news", which broke as confirmation came through that Queensland teenager Alyssa Azar, 19, had become the youngest Australian to conquer Everest on her third attempt.
"We are liaising with authorities and our heartfelt thoughts and support are extended to Maria's family, her friends, colleagues and students," a university spokesman said.
Monash is offering counselling support for students and staff.
In the past eight years, the couple had climbed summits in Alaska, Argentina, Turkey and Mt Kilimanjaro.
Strydom's death came a day after altitude sickness also claimed the life of Dutch climber Eric Arnold.
They were the first fatalities on Everest since expeditions resumed this year.
Mountaineering expert Alan Arnette said it was "very normal" for five to 10 people to die on Everest each year and altitude sickness was quite common.
"It's a dangerous mountain, people die on it, experienced people, inexperienced people, the sickness can be random," he said.
Arnette said altitude sickness was a broad term for number of problems, from high-altitude pulmonary edema where fluid gathers in the lungs, to high altitude cerebral edema where the brain swells.
"None of these conditions can be prevented other than by acclimatising slowly by taking several weeks to let your body adjust to the lower amount of oxygen density in the upper altitudes on Everest," he said.
Everest expeditions in 2014 were cancelled after 16 sherpas died in an icefall avalanche.
In 2015, another avalanche triggered by a 7.8-magnitude quake, killed 19 mountaineers at Everest Base Camp, prompting the cancellation of all trips.
It's expected to be a couple of days before the two bodies can be airlifted to Kathmandu and handed over to relatives.