Altitude Sickness

Nepal comprises 8 of the 10 highest mountain peaks in the world, including the gorgeous Mount Everest rising to an unbeatable altitude of 8,848 meters/29,029 feet. And of course, this is what makes climbers more vulnerable to altitude sickness than in any other parts of the world. The human body is fragile and cannot withstand extreme conditions and temperature. Not only for humans it’s equally important for all living organisms to adapt to the environment for survival. Hence, a standard way of ascending should always be maintained in order to avoid fatal consequences.

Causes of Altitude Sickness

Altitude Sickness is a medical condition caused by lack of oxygen in the atmosphere at high altitudes. Required precautions are always recommended and should be necessarily taken. First and foremost, it’s best if we know the major causes of the condition.

High Altitude

There are no chances that you’ll experience any kind of symptoms of Altitude Sickness if you are at an altitude not more than 1,500m/5,000ft. Logically, it can be understood that the effects are seen only at higher altitudes.

Low Oxygen Levels

As you ascend, the atmosphere start to get thinner and so does the level of oxygen in the air. This insufficiency creates imbalance in flood blow of the human body, which further leads to malfunctioning of muscles, certain other organs including the brain.

Rapid Ascending

It requires mountaineers to follow the standard speed at which they ascend steep mountain peaks. Moving too fast can cause fatal effects whereas slower movements lengthens the journey that initiates longer exposure to the altitude.

Lack of Acclimatisation

Acclimatisation is letting the body adapt to swift changes in the environment such as change in temperature, humidity and other relative components. The human body cannot bear instant changes and needs to adjust itself in order to tolerate higher level of further alterations, thus making acclimatisation a very important part of mountaineering.

Genetic Interference

Studies have shown that the genes ANP32D and SENP1 are highly responsible for altitude sickness, and people who have them are more vulnerable to the effects than people who don’t. Experts are able to find out who are more likely to get the sickness by measuring certain responses that their body provide during exercise. Before making any kind of high altitude journeys, its best to further know about Altitude Sickness and Acclimatisation. This makes it travellers to determine the symptoms when they have problems and then prepare for first aid through medical support and acclimatisation. Levels of altitude sickness can be sorted into three types. They are listed below as per their severity given the mildest at first.

Acute Mountain Sickness (AMS) [1,500m/5,000ft – 2,500m/8,000ft]

Not so severe, the symptoms of Acute Mountain Sickness can start to appear as soon as you elevate to 1,500 metres. Things usually do not get worse as the stage is mild and generally heals quickly. But if it progresses with climb, things can really get into trouble.


1. Loss of Appetite

2. Dizziness


4. Nausea and Vomiting

5.Accelerated Heartbeat

6. Muscle Pain

7.Short Breaths

8.Poor Sleep

9. Lethargy

10. Swelling of Body Parts

Beyond Acute Mountain Sickness, further lies more fatal forms of the sickness. Therefore, it’s best to prevent such circumstances by getting rid of the problem at the right time. Neglecting the symptoms can cause severe damage to the lungs and the brain.

High Altitude Pulmonary Oedema (HAPE) [2,500m/8,000ft – 4,000m/13,000ft]

Cases of HAPE are usually seen in casualties who ascend above 2,500 metres. Symptoms, generally, show up after a couple of days with exposure to the mentioned elevation. The condition is a result of built – up fluid in lungs that prevent adequate observation of oxygen from inhaled air.


1. Quick and Shallow Breathing

2. Abnormal Breathing Sounds

3. Extreme Fatigue and Weakness

4. Congestion

5. Tight Feeling Chest

6. Emission of Infectious Sputum, Later Followed by Blood

7. Accelerated Heartbeat

8. Fever

9. Blue or Grey Lips and Fingernails

10. Abnormal Behaviour Due to Malfunctioning of the Brain

11. Worsening of Symptoms During the Night

If HAPE continues to develop, the brain can receive severe forms of damages further leading to coma and finally death.

High Altitude Cerebral Oedema (HACE) [4,000m/13,000ft – above]

This stage is known to be the most fatal form of altitude sickness. As HAPE attacks lungs of the human body, HACE does even more severe by malfunctioning the brain relative to the effects of HAPE. The major relative effect is accumulation of fluid in the lungs as we mentioned earlier. This causes failure in observation of sufficient amount of oxygen from inhaled air, resulting inadequate supply to the brain. Ignoring the first stage symptoms can later end up with such consequences and probably even death. It’s important to remember that a person who has HACE becomes unable to walk on a straight line (Ataxia). This may help a lot in diagnosing.


1. Confusion

2. Fever

3. Fatigue

4. Unable to Walk on a Straight Line

5.Bizarre Behaviour

6. Altered State of Mind

7. Drowsiness

8. Loss of consciousness

HACE can kill its victim within a few hours. Drowsiness and loss of consciousness is seen shortly before death. Even if it’s too late, descending has been known to be the best cure for the condition.


Acclimatisation is the process of adapting the body to gradual changes in the external environment. Factors of changes may include change in temperature, altitude, humidity and photoperiod (pH). Changes of such factors within short period of time results direct effects that the body becomes unable to withstand. Laws of nature restricts limitation on survival with age and suitable conditions to live in. If any of the conditions are disregarded, death becomes certain. While mountain climbing, it becomes important to consider the external factors that can bring complications in the journey. Sudden change in altitude, temperature and air pressure can result to a wide range of fatal consequences to the body. Thus, to maintain a healthy climb, acclimatisation has always been believed to be one of the vital parts of mountain climbing. At sea level and normal conditions, the level of oxygen in the atmosphere tends to be about 20%, which is, undoubtedly, the very basic requirement for human survival. But, as the altitude reaches 1,500 metres / 5,000 feet, density of air starts to decrease causing the level of oxygen to decline too. Relatively, with elevation, the temperature also start to drop, making it even more demanding to climb further. Lower level of oxygen in the blood does not allow the body to function properly. Therefore, it’s necessary to consider the following things with respect to acclimatisation.

1. Increase Altitude Gradually

2. Lots of Water to Prevent Dehydration

3. Avoid Carrying Overloads

4. Warm Clothes All the Time

5. Avoiding Smoking and Alcohol

6 Extend Rest If Any Kind of Symptoms of Mountain Sickness if Seen

7. Descend Immediately If the Symptoms Get Worse

If these notes are taken seriously, climbing and exploration can always be fun. But if ignored, fatality shall show its dominance.