"The physiology of a healthy person trying to adapt to high-altitude looks a lot like a disease state of someone who is trying to tolerate a condition like heart failure, where blood flow to tissues is reduced," Johnson said.
ANALYSIS: Makings of the Deadly Everest Ice Avalanche
Recognizing these parallels has allowed scientists to pursue treatments and drugs for people under both kinds of distress. Diamox, which is often used to prevent altitude sickness, was originally designed to treat high blood pressure. And in recent work, Johnson's team has been trying to figure out how to combat the build-up of fluid in the lungs of people with heart failure, a problem that also plagues high-altitude climbers.
Studying climbers on Everest also allows researchers to better understand the effects of hypoxia, a lack of oxygen supply to tissues, said Cynthia Beall, an anthropologist at Case Western Reserve University in Cleveland.
"One of the beauties of high-altitude studies of healthy people is we can look at the range of things that hypoxia does," Beall said. "We can separate the disease from the hypoxia."