Hiking officials attributed most of the deaths to weakness, exhaustion and delays on the crowded route to the 8,850-meter (29,035 feet) summit.
Robin Haynes Fisher, 41, died in the so-called "death zone" known for low levels of oxygen on descent from the summit, Mira Acharya, a tourism department official, said.
He is the eighth fatality on Everest in the current climbing season that ends this month.
“He died because of weakness after a long ascent and difficult descent,” Murari Sharma of the Everest Parivar Treks company that arranged his logistics told Reuters. “He was descending with his sherpa guides from the summit when he suddenly fainted."
Fellow guides changed Fisher's oxygen bottle and offered him water, but could not save him, Sharma said.
Garrett Madison of the U.S. based Madison Mountaineering company that sponsors climbers to Mount Everest said many were not "well qualified or prepared climbers" and were without the support necessary to ascend and descend safely.
"If they were with a strong and experienced team they would have likely been fine, but with minimal support, once something goes wrong it's tough to get back on course," Madison told Reuters.Mount Everest can also be climbed from Tibet and casualties have been reported from there this season too.