Sergey Kofanov

42 years, Australia

4 years ago


how to face mountain sickness

I experienced mountain sickness for the first time when I was 18 years old, during my first training camp in Tien Shan, near Almaty (Kazakhstan). It was my first climb and the altitude was about 4000 meters. The summit has an unpronounceable name: Manshuk-Mametova. Sickness, nose bleeding, diarrhea accompanied me and it all ended up with a large-scale rescue operation. I didn't finalise the first climb of my life.

After this incident, for seven years, I thought that climbs above 5000 meters weren't for me and that my body just wasn’t structured properly, to even begin to dream about a real high-altitude climb. The Pamirs, Tien Shan and Himalayas peaks seemed to me an impossible dream. Athletes, who climbed them, seemed to me gods. So mostly I focused on technical, but not high-altitude climbs that wouldn't involve the risk of facing mountain sickness. Although, I must confess, a couple of years after the first case, I decided to climb Mount Elbrus (5642 m). Fortunately, it didn't end up with a rescue operation (it went closely btw), but only convinced me of my inability to climb peaks above 5000 meters.

I can't say I was doing something wrong, or that I was missing information about mountain sickness. I grew up in the Ural Mountains, which gave the world such athletes as Anatoly Boukreev, Eugeny Vinogradsky, Alexey Bolotov, Alexander Klenov, Sergey Borisov, Mikhail Davie... the list is almost endless. I talked with all these people almost every day during our trainings and sport camps, but it didn't help me to understand how to face mountain sickness. I knew the theory, but I was failing while trying to practice it. 20 years back, I would recommend to that 18-year-old boy to never give up and insist on facing mountain sickness. 

Only now I understood that the problem was more psychological than associated with adaptation to my body altitude limitations. But on the other hand, I can’t say that the seven years that I've been avoiding high-altitude climbing, were useless. Over the years, I became the youngest sport master in Russia, I won a national championship, I was player-coach of my county team... Maybe it was necessary for my training and I wouldn't be able to climb twice Mount Everest (8848 m), ascent the west pillar of Mount Jannu (7771 m) in alpine style, and climb the other 7000 m altitude Pamir, Tien Shan, the Himalayas and Karakoram, without this experience. But I can say that my relation with mountain sickness lasted for 20 years, that it is not over yet, and I can definitely share with you information about what mountain sickness is and how to fight it.

However, I don't invite you to refer to this page content as an exact instruction. Each case is unique, and it isn't always possible to make professional diagnoses, or prescribe the exact medication. Medical researches in this field aren't completed yet, and always discover something new. So you better worry about finding the most recent information about mountain sickness.

In my essay, I will describe the acclimatization process and its role during the mountain sickness facing process in such situations as HACE (High Altitude Cerebral Edema) and HAPE (High Altitude Pulmonary Edema). Moreover, I will give you some practical advice about the use of such popular medications as Diamox and Nifedipine.


The process of the body adaptation to altitude is called acclimatization. Some mistakenly think that acclimatization is related only to the lack of oxygen, but our body adapts to the new atmospheric pressure, low temperature and low humidity during the adaptation process. Acclimatization is a complex process associated with physical body changes. The result of these changes are the new for us composition and blood viscosity, breathing depth and frequency, some parts of lungs don't work equally, new enzymes are allocated, and so on. This process is reversible, which means that after the way  back, the body gradually returns to its normal condition. The time to restore the body to its normal "settings," depends on the altitude to which it adapted. For example, after climbing a peak over 7500 meters, the composition of your blood will return to its normal balance after approximately 2-3 months.

Ama Dablam Climb
After climbing a peak over 7500 meters, the composition of your blood will return to its normal balance in 2-3 months.

As a rule, the acclimatization process begins when you exceed 2500 meters altitudes. It means that many people can climb from sea level to 2500 meters without experiencing any signs of mountain sickness, although, of course, there are exceptions. However, if you try to climb above, let's say up to 3000 meters, without giving your body the time to adapt to new conditions, then it is likely that you will have to face symptoms such as poor sleep, headache, dizziness, hallucinations, stomach-ache, nausea and weakness. The higher you climb, by not having a proper acclimatization level, the more serious will be the consequences, including even death.

In order to get used to a new altitude, your body needs long enough time that may depend on the individual characteristics of your body. The only reliable way to get rid of the symptoms of mountain sickness, is to descent fast until your body adapts. General experience shows that after 3000 meters, the human body can, without serious consequences, climb up to 500 meters per day. When gaining each increment of 500 meters, the body needs from one to two resting days to get used to the new environment.

The higher the altitude, the more time you need to adapt, so you can't refer directly proportional to acclimatization. To climb over 5000 meters, you will need 7 to 9 days and 12 to 15 days to climb over 6000 meters. More than 7000 meters altitudes require you 19 to 21 days while peaks exceeding 8000 meters require about 40 days. Everest is so special to require up to two months in order to climb 8848 meters.

It is good to know that the human body has a limit to adapt to the altitude. There are no conditions that will allow you to reach that level of acclimatization, which would allow you to live at an altitude of over 6000 meters. At this point, logically you may ask yourself how people climb all of these peaks higher than 8000 meters without supplementary oxygen?!? Because time spent above 6000 meters during these climbs are inherently short, even if some of them last several days. Above 6000 meters your body won't survive. It will die gradually, by ceasing organs one by one. Tibetans and Sherpas are the highest living peoples of the world. Some Tibetan villages are located at an altitude of 5000 meters. Therefore, we can say that these people are constantly subjected to acclimatization and it is easier for them to climb such giants as the Himalayas.


Mountain sickness (aka altitude illness) is a common term used to describe a variety of disorders humans experience at certain altitude. Typically, mountain sickness occurs in case of fast ascents, when the body doesn't have enough time to adapt to the altitude. Mountain sickness may be expressed under various forms. The most serious ones are HACE (High Altitude Cerebral Edema) and HAPE (High Altitude Pulmonary Edema). But these serious situations occur very rarely on trekking routes and are more probable while exceeding 6000 meters climbs. It is believed that a person is 100% guaranteed to get HACE in case of exceeding 8000 meters of altitude. Its severity can be different and depends on the acclimatization level of the climber and his experience above 8000 meters of altitude. If a climber does everything right and doesn't overstay in the "death zone", Cerebral Edema just won't have time to reach its critical stage. But if the climb schedule interferes with, for example, an unplanned overnight stay on the descent, the risk of falling into coma and never getting out of it increases dramatically.

Everest Broken Tent
"It is believed that a person is 100% guaranteed to get HACE in case of exceeding 8000 meters of altitude."

The treatment in this case may only be one: a sharp descent next to supplementary oxygen and medicines such as Dexamethasone (in case of cerebral edema), or Nifedipine (in case of pulmonary edema). At high altitudes, any disorder develops at a high-speed locomotive rhythm, and sometimes every moment counts. Any delay or lack of coordination puts at risk a successful rescue operation. But, like I said, all these horrors are related only to high-altitude climbs. In case of trekking climbs or alpine climbs, mountain sickness is often manifested in the weaker form and cerebral or pulmonary edema are extremely rare here.

Work is the main way to face mountain sickness. As long as you don't stand and move your body, it works more actively. It means it is facing aggressive foreign conditions more actively. Without noticing it, you make more frequent and deep breaths, your heart beats faster and faster by forcing blood through your body. But as soon as you sit down to relax or go to sleep, your body immediately begin to feel the altitude. That is why often the first mountain sickness symptoms aren't observed immediately after the arrival but in the evening or by night. The presence of mild mountain sickness symptoms indicates that your body processes started their adaptation. These minor symptoms shouldn't scare you as they usually disappear after one or two days of rest. In order to make the acclimatization process smoother before moving to a higher camp, climbers and trekkers go to the new place once or twice, and then come back to rest.

In most cases, mountain sickness is manifested under the following forms:

  1. Disturbed sleep
  2. Digestive problems
  3. Headache
  4. Appetite loss
  5. Irritability
  6. Chronic weakness or tiredness
  7. Inconsistent breathing
  8. Dizziness
  9. Nausea
  10. Hallucinations
  11. Inability to think clearly
  12. Movement problems 

To determine the severity of each manifestation, it is common to use a scale from 1 to 4, where 1 stays for complete absence of symptoms, and 4 is the most severe form of symptoms manifestation. In case you evaluate your condition with 3 points, then you urgently need to begin descent until your body will feel properly.

Stomach problems are usually caused because the bacteria, that lives in our digestive tract in charge of processing food, depends on oxygen as well and therefore their number is drastically reduced in case of oxygen lack, which, at its time leads to digestive tract malfunction.


  • Do not over-exert yourself, keep a slow pace, pay attention to your breathing. From time to time force yourself to breathe more deeply and more frequently. It's called hyperventilation.
  • Avoid dehydration by drinking 2 to 3 litres of proper water per day. Coffee, tea, cola and beer don't count, because they have a diuretic effect, and can significantly aggravate the situation.
  • Take it easy on alcohol, smoking and other stimulants whilst climbing and trekking.
  • Try not to climb more than 500 to 700 meters per day, give your body time to get used to a new altitude by resting for a couple of days.
  • If you suffer from mountain sickness, don't rush, and don't climb above until body will acclimatize and symptoms will disappear.
  • If symptoms persist despite the rest and are increasing, then immediately go down until that altitude where symptoms will disappear. Relax a day or two at this altitude, and only then try to climb again.
  • Don't stay too long on the summit, or high passes - try to reduce the time spent on them to a minimum and go down immediately.
  • Work only with experienced guides who understand the risks of mountain sickness and are trained to deal with it.


Why the risk thrombosis is much higher on altitudes?

During the altitude adaptation process, our hematopoietic organs begin to produce blood with large amount of erythrocytes, aka red blood cells. That red blood cells are responsible for transporting oxygen in our body. The red blood cells increase leads to the fact that our blood becomes thicker and our heart "pumps" it heavier into the circulatory system. Besides the additional effort of the heart, thick blood can cause blood clots. In addition, thin blood vessels begin to suffer.  You have them, for example, in our eyes, because blood enters there harder.

I heard that I should drink sleeping pills before going to bed in order to sleep better and relax. Is it true?

Well, you can do it, however I wouldn't recommend you to experiment with sleeping pills until you don't gain great experience with the acclimatization process. 

Does Diamox accelerate the acclimatization?

It does, but personally I'm not a big Diamox fan. It makes me feel a little sick, so I try not to use it. Perhaps, in my case, it's just an allergic reaction, as many friends of mine successfully use Diamox while climbing and trekking. I recommend you to try Diamox at home. If you don't experience any side effects, then you can try to use it on the mountains. Since Diamox has a diuretic effect, you need to consume more liquids at high altitudes. I wouldn't recommend using Diamox at altitudes not exceeding 4500 meters. It is highly recommended to consult your doctor regarding its consumption and dosage.

Will I still need acclimatization in case I would be using supplementary oxygen during the entire climb? 

It depends on factors such as oxygen dosage and your climbing altitude. By the way, the use of oxygen doesn't allow you to avoid the acclimatization process and mountain sickness symptoms. For instance, at 4 L/min oxygen flow rate, the perception is reduced by 2500 meters altitude. So if you climb Mount Everest by using supplementary oxygen, your perceived altitude on its summit becomes equal to about 7000 meters. It means your body still needs acclimatization in order to climb 7000 meters without using supplementary oxygen.

If you have any further questions about acclimatisation process and mountain sickness, please leave a comment below - I would be happy to answer it.

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