ACCLIMATIZATION

HIGH-ALTITUDE CONDITIONS

I will try to make it easier for you to reach your dream Everest. The mountain conditions differ from those you left behind when you set out on your expedition, primarily due to the decreasing atmospheric pressure with altitude, which leads to a reduced availability of oxygen in the air, a drop in air temperature, a decrease in humidity, and an increase in UV radiation.

GOLDEN RULES OF ACCLIMATIZATION

The human body has great adaptability to new conditions, but it needs time for that.The main problem is the lack of life-giving oxygen, which decreases with every meter of altitude gained. We start to breathe faster, and the number of red blood cells in our blood increases, which transport the missing oxygen more effectively. The process of acclimatizing the body to what it encounters in the mountains is called acclimatization. Most people, after a sufficiently long time (weeks), have no problem adapting to altitudes of 5000 - 5500m above sea level (the base camp level under Mount Everest).

Above 5500m above sea level, long-term existence is out of the question for most people.We stay there for as short a time as possible, because day by day our bodies deteriorate. A gradual acclimatization process allows a person to survive without additional oxygen in extreme conditions, such as those found at the summit of Mount Everest. In 1875, two members of the Zenith balloon crew, who reached an altitude of 8000m above sea level within a few hours, were not so fortunate, and the lack of oxygen at that height caused them to lose consciousness and die.

What to do to acclimatize well?Follow these rules: spend the first night at a maximum altitude of 2500m. Above 2500m above sea level, gain altitude slowly each day. The height difference between successive overnight stays should not exceed 500m. Overcoming larger height differences during the day is not a problem, but spend the night only 500m higher than the previous one. If you plan to stay overnight more than 500m above the previous one, take a rest day before or, if necessary, after that ascent - to give your body time to adapt. After every 1000m of altitude gained gradually, take a rest day, a so-called REST DAY. Avoid direct transport at altitudes above 2500m.

If it is not possible to maintain the pace of altitude gain according to the above rules, it is essential to closely monitor your body and respond immediately to the appearance of symptoms of altitude sickness, as well as to use a medication that reduces the risk of altitude sickness - acetazolamide (Diuramid). Acetazolamide (Diuramid) is used in the prevention of acute mountain sickness starting 24 hours before sudden exposure to altitudes above 2500m above sea level and ending after 2-4 days of staying at the maximum planned altitude, at a dose of ½ tablet every 12 hours. When using acetazolamide (Diuramid), it is necessary to replenish electrolytes.

Following the above rules may seem impossible for those of you for whom the mountains are not new, especially when the next camps are nearly 1000m apart and getting to the base at 4000m above sea level requires a helicopter.On expeditions to peaks of 6000-7000-8000m above base, we follow the principle of "first touch, then sleep." On subsequent exits from the base, called rotations, we first touch the altitude of the camp, in the next outing we sleep there and touch the altitude of the next, higher camp. In the following outing, we sleep in that next camp and touch the altitude of the higher one, and so on.

The pace of acclimatization is individual for each person, it does not depend on gender or the body's endurance. Some acclimatize faster, others slower; this should be respected, and the pace of ascent should be adjusted to the weakest – you might also have a bad day! Before the trip, it is worth drawing a chart of the planned trip's altitude and preliminarily deciding on rest places and times. It is advisable to reserve a few days for unexpected situations (about 20% of the trip time), which will allow for more comfortable operations in the mountains.

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DO YOU WANT TO LEARNMORE?

If you want to better prepare yourself health-wise for trekking or a high-altitude expedition, you will find an expanded version of the guide in the ebook"High-altitude medicine in practice – a guide for trekking and expeditions" >>

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You will also learn practical knowledge about how to act in emergency situations in the mountains in the online training"High-altitude first aid" >> - designed for people planning trips to high altitudes.

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You will find a detailed composition of the expedition first-aid kit and a precise instruction for preparing the expedition first-aid kit and personal rescue kit in the ebook"Expedition first-aid kit – a complete medical guide" >>

ARE YOU PLANNING A TREKOR A HIGH-ALTITUDE EXPEDITION?

If you want to check whether your health condition allows you to safely participate in trekking or a high-altitude expedition, it is advisable to take advantage of a medical consultation >> or a telemedicine expedition package >>

This way, you can assess health risks in advance, prepare appropriately for the trip, and increase safety while at high altitudes.

07 March 2026

The company was established in 2004. The goal of MedEverest is education in the field of mountain medicine and the dangers of high altitudes. I deal with all medical aspects of staying at high altitude. I organize medical support for trekking and high-altitude expeditions.

Specialist Medical Practice Medeverest Robert Szymczak based in Gdańsk (80-360), at ul. Bolesława Krzywoustego 19F, NIP: 5841943576, REGON: 220148318.

Also checkStore regulations >> Implementation: ColinMedia.eu >>