Research at 5,000 metres: what extreme environments teach us about human health

What happens to the human body and brain when oxygen becomes scarce? It’s a question that has fascinated scientists for decades - and one that is becoming increasingly important as more people travel, work and live at altitude.

For researchers from the University of Birmingham, answering it has meant taking science out of the laboratory and onto the mountain trail.

In 2025, Birmingham researchers were part of a collaborative expedition studying acute mountain sickness (AMS) along the Everest Base Camp route in Nepal - a setting where villages such as Namche, Dingboche and Lobuche sit at altitudes many people will never experience in their lifetimes. Working at heights approaching 5,000 metres, the team gathered physiological, cognitive and sleep data in conditions that test both participants and researchers alike.

Why study health at altitude?

Acute mountain sickness remains a significant risk for people ascending to high altitude, even when they follow established guidance on acclimatisation. Symptoms such as headaches, nausea, fatigue and sleep disturbance are common, yet predicting who will be affected — and when — remains a challenge.

The Birmingham led research focused on whether overnight blood oxygen saturation, measured using wrist-worn pulse oximeters, could provide a more reliable way to detect or predict AMS than traditional self-reported methods such as the Lake Louise Score. Understanding these physiological changes is not only relevant to trekkers and climbers, but also to broader questions about how the brain and body respond to low oxygen environments.

Science beyond the lab

Conducting research at altitude is not simply a matter of transporting equipment from one place to another. Fieldwork on the Everest trail meant researchers working in cold, remote, low oxygen environments, often travelling alongside trekking groups and adapting scientific protocols to real world constraints.

Participants who chose to take part wore pulse oximeters overnight, completed brief cognitive and sleep assessments, and in some cases used smartphone-based tools to contribute additional data. These methods allowed the team to examine how altitude influences blood oxygen levels, sleep quality and cognitive function as people ascend.

Importantly, participation was entirely voluntary, with no financial incentive — a reminder that much expedition research relies on trust, clear communication and the willingness of individuals to contribute to science in challenging conditions.

Collaboration at the core

This research was not undertaken in isolation. The study was a collaboration between the University of Birmingham, the University of Chichester, University of Oxford, and Imperial College London, with logistical support from Mountain Kingdom’s, Mountain Legends, Intrepid and Earth’s Edge (to name a few) in the field. Such partnerships are essential when research questions demand scale, specialist expertise and access to extreme environments.

For Birmingham, the project reflects a broader strength in interdisciplinary research spanning physiology, psychology, brain function and environmental science. It also demonstrates how collaboration enables universities to tackle complex health challenges that cannot be addressed within the boundaries of a single discipline or institution.

Why this kind of research matters

At first glance, studying health on the Everest trail may seem niche. But the insights gained have far wider relevance. Understanding how the human body responds to oxygen deprivation informs not only mountain medicine, but also research into sleep, cognition and physiological stress more generally.

There are also practical implications. Improved methods for predicting AMS could contribute to safer trekking and climbing practices, benefiting both visitors and those who work at altitude. In this sense, research at 5,000 metres feeds directly into real-world impact — one of the defining ambitions of research at the University of Birmingham.

The human side of discovery

Perhaps most compelling is the reminder that research is a human endeavour. Behind every dataset collected at altitude are cold nights, careful planning, ethical considerations and the challenge of maintaining scientific rigour far from controlled laboratory conditions.

For early career researchers and students, projects like this show what a research career can look like: intellectually demanding, collaborative and, at times, physically demanding. They also highlight the value of curiosity driven research that pushes boundaries — geographically as well as academically.

Looking ahead

As analysis of the data continues, the findings from this work will contribute to a growing body of knowledge about human performance and health in extreme environments. But even now, the study stands as a powerful example of how Birmingham researchers are willing to go — quite literally — to advance understanding.

Research at 5,000 metres reminds us that some of the most important scientific insights emerge not from comfort, but from challenge. And it is in these extreme settings that the University of Birmingham continues to demonstrate the reach, relevance and ambition of its research.