Altitude Sickness

Altitude Sickness

In a challenging environment, high altitude serves as a model for how environmental influences can make us sick when they surpass the adaptability of humans. Individuals from low-altitude regions who go to high-altitude regions, mostly for adventure, run the risk of developing high-altitude sickness. The desire for high-altitude adventure and trekking is growing worldwide, so newcomers need to be aware of the risks and physical difficulties that come with prolonged exposure.

With the rise in popularity of high-altitude adventure, comes an increased risk of altitude sickness, which affects over 25% of those who climb to 3500 m and over 50% of individuals who climb over 6000 m. At a high altitude, Acute Mountain Sickness (AMS) manifests in healthy individuals in a matter of hours. Fatigue, headache, eating disorders, feeling sick, throwing up, dizziness, and exhaustion are some of the signs.

Most of the time, these symptoms go away on their own after 20 to 35 hours, negating the need to drop to a lower altitude. Just under one percent of AMS cases, however, progress to potentially fatal high-altitude cerebral edema, a condition that manifests as decreased awareness.

The chance of getting altitude sickness varies depending on the climber and the particular ascent. The climbing pace, elevation, air pressure, duration of high-altitude sleep, tiredness, weather conditions, pre-acclimatization, history of the high-altitude disease, and medicines are among the variables that affect each ascent.


The process of acclimatization is a complicated and poorly understood way to reduce altitude sickness. It affects almost the whole body, however individual limitations will differ. When people relocate to high elevations from lower elevations, poor acclimatization leads to a variety of indicators, including fatigue, headache, shortness of breath, and nausea.

These symptoms are together referred to as acute mountain sickness. If the ascent is not continued, these symptoms rapidly resolve; on the other hand, if the climbing process continues despite indicators, HAPE (high altitude pulmonary edema) or HACE (high altitude cerebral edema) may progress. These are the two main severe forms of altitude sickness.

Although acclimatization is not very well understood from a medical point of view, it works just fine to reduce the chances and even avoid altitude sickness. Every one of our Himalayan trekking programs has acclimatization days to make sure that you do not suffer from altitude sickness.


Reaching a high altitude too quickly is the main cause of sickness associated with altitude. In addition to that, altitude sickness can also result from prolonged stays at high altitudes. At the level of the sea, the standard atmospheric pressure is 760 mm Hg, and the oxygen content in the air is around 21%.

The oxygen content doesn’t change when you ascend higher, but the air pressure does. For instance, the air pressure at the summit of Mount Everest is approximately 228 mm Hg. Because the air is less compact at lower pressure, there are fewer oxygen molecules in every breath you take.

Each breath at an altitude of nearly 18,000 feet contains approximately fifty percent of the oxygen present at ground level.

Your lungs and cardiovascular system have to operate harder if oxygen is low within the bloodstream. Your respiration and pulse rates increase as a result. In order to transport a greater quantity of oxygen, the body produces additional red blood cells in return. The level of oxygen in the blood rises as you breathe quickly, but they do not approach quantities found at sea level.

The normal time for the human body to adjust to a shift in altitude is one to three days. Individuals who proceed to a higher altitude too quickly without giving themselves the time to acclimate are most susceptible to altitude sickness.

How to Cope

Even those with extremely mild signs should still climb, albeit much more slowly. Nonetheless, you should notify the trek guide or tour guide if you develop even mild symptoms.

For those with symptoms that are more severe, you should rest, drink lots of water, and avoid smoking or other activities that might lower oxygen levels in the blood.

Altitude sickness may be treated using a variety of possible methods. In most cases, the best course of action when experiencing signs of altitude sickness is to relocate to a lower altitude. You might be able to climb again when you’ve acclimated.

A patient suffering from severe altitude sickness and breathing difficulties may benefit from receiving pure oxygen. This medication is frequently administered by doctors at Highlands.

Headaches can be treated with acetaminophens, such as those found in Tylenol. You are unlikely to find Tylenol in Nepal, however, you will get an alternative that works just fine. An anti-inflammatory drug called ibuprofen may also be useful.

To lessen the effects, you might also take some pills. Acetazolamide accelerates breathing and fixes the chemical abnormality in the blood brought on by altitude sickness. On the other hand, there are a few potential negative effects of this medicine, such as tingling in the cheeks, fingers, and toes, frequent urination, and in rare instances, clouded eyesight.

Dexamethasone is a type of steroid that is another medication you can use to reduce inflammation and immunological function. It can lessen the likelihood of severe altitude sickness and other issues. Nevertheless, the drug may cause exhilaration, and stomach ache, among other undesirable side effects.