How does the body acclimate to the thin air on Mount Everest?

How does the body acclimate to the thin air on Mount Everest?

How the Human Body Acclimatizes to the Thin Air on Mount Everest

When we discuss the ultimate test of human strength, endurance, and spirit, Mount Everest, standing at an elevation of approximately 29,031 feet, inevitably springs to mind. The challenge it poses physically and mentally is equally matched by the strain it places on the body’s cells, organs, and systems, as they all seek to acclimatize to conditions of drastically thin air. It’s this unique capacity for acclimatization that allows humans to summit Mount Everest, the ‘Roof of the World.’

The Decreasing Atmospheric Pressure

Acclimatization begins by understanding the basic issue climbers face on the Everest – decreasing oxygen levels. As one ascends closer to the stratosphere, the atmospheric pressure falls gradually. This means fewer molecules in every breath you take, leading to decreased oxygen and the onset of altitude sickness, marked by dizziness, nausea, headaches, and shortness of breath.

The Remarkable Body Response

In such hostile conditions, the body kicks into survival gear. Initially, we experience hyperventilation as the body gasps in more air, attempting to compensate for the lack of oxygen. Concurrently, the heart rate and blood pressure rise to boost the blood flow to the muscles and brain.

The Role of Red Blood Cells & Hemoglobin

The body further acclimatizes by producing more red blood cells, that carry oxygen, to counteract the lower oxygen concentration. Additionally, the binding affinity of hemoglobin, the protein that carries oxygen in the blood, is reduced. This means it delivers oxygen to the tissues more willingly, aiding their need for oxygen.

Longer-Term Adaptations

If climbers decide to stay longer, they undergo further physiological adaptations. Their bodies generate more capillaries – the small blood vessels where the exchange of oxygen and nutrients occurs. Mitochondria, our cells’ energy factories, also increase to allow for more efficient use of the available oxygen.

Genetic Signature

Amazingly, genetics also play a part in acclimatization. Studies have discovered certain Tibetans and Sherpas share a particular gene variant inherited from extinct humans – the Denisovans – which allow their bodies to adapt more efficiently to low-oxygen environments. These peoples’ bodies increase their Nitric Oxide production – a molecule that improves blood flow and oxygen delivery.

Acclimatization: A Matter of Life & Death

Despite the incredible adaptability of the human body, sudden exposure to such high altitudes without proper acclimatization can lead to fatal conditions such as high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE).

Thus, climbers undertake incremental climbs, ascending higher each day, then descending to sleep at a lower altitude. This step-by-step approach allows the body time to adapt to the low oxygen levels, reducing the risks of altitude sickness.

The Wonders of Human Endurance

Acclimatization manifests the incredible resilience and adaptability of the human body. The capacity to adjust our physiological functioning in the face of environmental adversity showcases an inspiring narrative of human endurance and survival against all odds.


A few common queries related to acclimatization to Mount Everest:

Q1: How long does it take to acclimate to the high altitude on Everest?

A: Normally, climbers spend around two months on Mount Everest, with the majority of the time spent acclimating to the high altitude. This allows the body to develop more red blood cells to carry the lesser available oxygen.

Q2: What happens if the body fails to acclimatize?

A: If the body fails to acclimatize, climbers can encounter severe altitude sickness, known as Acute Mountain Sickness (AMS). In worst-case scenarios, it can lead to life-threatening conditions like HACE or HAPE.

Q3: Can everyone acclimate to the high altitude on Mount Everest?

A: Everyone has a different capacity for acclimatization based on genetics and individual physiology. It’s not guaranteed that everyone can acclimate and survive at such high altitudes, even with considerable training and preparation.

Q4: Is it possible to permanently live at high altitudes like Everest?

A: Although our bodies can acclimate to high altitudes to a certain degree, living permanently at the extreme altitudes of Everest isn’t feasible due to the drastic changes required by our bodies and the harsh environmental conditions.

Q5: What role does hydration play in acclimatization?

A: Proper hydration is crucial as it aids in maintaining blood volume and preventing symptoms of altitude sickness. Staying hydrated also helps to counteract the dryness of the air at high altitudes.