How to prevent Altitude sickness during a trek in Nepal?


Have you ever hiked or trekked to the higher altitudes and felt something different with your body? Well, if you’re an adventure lover then you might have gone through such an experience at some point which is called altitude sickness (also known as mountain sickness).

Altitude sickness is a nightmare to all high-altitude trekkers and adventurers be they pro or beginners. Not only to the hikers but even for those who have been to the high-elevation locations for the first time might experience altitude sickness too.

In general terms, altitude sickness is a condition that occurs when a person ascends to a higher elevation too quickly, not giving enough time to their body for the adjustment with the reduced oxygen level and changes in the air pressure.

In mountaineering, altitude sickness is also known as AMS (Acute Mountain Sickness). Altitude illness, hypobaropathy, Acosta disease, puna, and soroche are other common names that are used for altitude sickness.

It can be a serious condition if not properly addressed, so it’s important to take precautions when planning a trip to a high-altitude destination. In this blog post, we will discuss the most asked question “How to prevent altitude sickness?” Additionally, we’ll dive into all the topics related to altitude sickness especially while trekking in Nepal.

Generally, above which altitude does altitude sickness occur?


During your trip when you exceed the elevation of 2,500 meters (8,000 ft) after 6 to 24 hours, you might develop the symptoms of altitude sickness.  

In mountaineering 8,000ft to 12,000ft above sea level is considered high altitude, whereas 12,000ft to 18,000ft is considered to be very high altitude, similarly altitude above 18,000ft is known as extremely high altitude. 

What is the cause of altitude sickness?

During the trek when we advance to a higher altitude, the atmospheric pressure is very low. Due to this, the accessibility of oxygen drops to a very low level. So, our body requires some time to adjust to that altitude. The rapid gain of altitude without proper acclimatization leads to altitude sickness. The sudden and rapid elevation to higher altitude is the prime cause of altitude sickness.

Even if you have already been to high altitude and didn’t suffer from altitude sickness, it is not guaranteed that you will be immune to altitude sickness so you must be careful. 

What are the types of altitude sickness?

There are three types of altitude sickness. They are listed below:

Acute Mountain Sickness

While elevating to a higher altitude, the sickness caused due to depletion in air pressure and availability of low oxygen levels is called acute mountain sickness. It is the mildest form of altitude sickness. It is pretty common but can take bad shape if ignored and put the victim’s life in danger.

High altitude pulmonary edema (HAPE)

It is assumed that in HAPE the blood vessels in the lungs squeeze together which results in increasing pressure, which causes fluid to leak from the blood vessels to the lung tissues and eventually into the air sacs as well. It occurs after the worsening of AMS. It can be life-threatening and also a common cause of death from altitude sickness. 

High altitude cerebral edema (HACE)

It is a serious medical condition in which the brain swells with fluid because of the physiological effects of traveling to a high altitude. It is the worst condition of AMS. 

Symptoms of altitude sickness. 


If you are suffering from altitude sickness then you will be developing the following symptoms:

  1. Headache: The headache you suffer during altitude sickness is usually quite intense and quivers. It can last up to five days. If not cured in time the headache worsens in the company of coughing, straining, and so on. 
  2. Dizziness:  You might also feel dizziness along with a headache. 
  3. Nausea and vomiting: You might get that uneasy and uncomfortable feeling in your stomach which makes you feel like you are going to vomit. In actuality, you might even vomit. 
  4. Fatigue and loss of energy: Without even doing anything you might feel very tired and feel like having no energy in your body. It can be both mentally and physically.
  5. The problem with breathing: The air pressure at higher altitudes is very low and the availability of oxygen is also very low. So due to a lack of oxygen and enough air pressure, you will be having difficulty breathing and might need supplementary oxygen to prevent the situation from worsening. 
  6. Problem with sleep: Due to the reduction of oxygen at a high altitude, you will be having breathing complications, but your body struggles to restore normal oxygen levels. So, because of this complication, you might have difficulty sleeping.
  7. Loss of appetite: As a consequence of less oxygen in the air of the Himalayas, the body produces a high level of leptin. Which is a hormone that is responsible for reducing hunger. 

The symptoms of altitude sickness develop between 6 to 24 hours and it takes around a day or two for your body to adjust to that altitude. If the situation gets worse then the AMS will develop into HAPE and the symptoms of HAPE are more vulnerable than the moderate effects of altitude sickness. The symptoms are: 

  • cyanosis (blue shades to the skin or lips)
  • tightness or heaviness in the chest.
  • tiredness and weakness.
  • breathing difficulties, even when resting.
  • a continued cough, bringing up pink or white frothy liquid (sputum)

On the other hand, the symptoms of HACE are listed below:

  • loss of consciousness 
  • hallucination
  • rapid heartbeat 
  • the discomfort of an eye in bright light 
  • lack of energy 

We must be very aware after the symptoms start to develop because the worsening of the condition can lead to death.

How to prevent Altitude Sickness?

Altitude sickness can take a huge form of life-threatening if ignored. There are thousands of examples of people not being able to conclude different trekking due to altitude sickness. Living up to the saying ‘prevention is better than cure here are some preventive measures to follow at high altitudes:

  • Avoid ascending more than 500m a day
  • Have a rest day after gaining an altitude of 600 to 900m
  • Avoid flying directly to high-altitude areas
  • Drink plenty of water and don’t let yourself feel thirsty. If you feel thirsty then understand that you are slowly getting dehydrated.
  • Strictly avoid alcoholic products and smoking 
  • Consume a high-calorie diet
  • Avoid exposure to extreme sunlight 

If you are following these measures then you are quite far away from altitude sickness. 

How to treat altitude sickness?

First thing first, if you or your fellow trekker is developing the symptoms of altitude sickness, do not panic and follow these natural methods:

  • Stop the trek and rest where you are
  • Do not ascend any further for at least a day or 2 days 
  • Drink enough water to stay hydrated (4 liters per day)
  • Avoid smoking and alcohol
  • You can eat garlic and cloves which will help to thin the blood vessel and increase the flow of blood in the body.
  • Do not do any kind of tough exercise
  • Understand the intensity of the altitude sickness and descend right away if the symptom starts to develop more.

At high elevation, we highly suggest not to use painkillers because the painkiller might be just suppressing your symptoms due to which you might feel better but inside the body the symptoms develop gradually and make the condition worse. When the effect of the painkiller fades off then you will already be in a very vulnerable stage. So, avoid using painkillers. But during an emergency, you can use the following medicine for the following symptoms:

  • Paracetamol to cure headache 
  • Anti-sickness medicine like promethazine to cure nausea
  • Acetazolamide to prevent sickness

Role of acclimatization in Altitude sickness?

Acclimatization is the process of adapting to a new environment, allowing the body to maintain its composition. Environmental changes such as a changes in altitude, temperature, pH, and humidity are responsible for internal changes in our bodies. The prime cause of altitude sickness is ascending too fast at high altitudes. 

In case of altitude sickness, it takes around 1 to 3 days for proper acclimatization. We must be patient and give some time to our body so that it can adapt to the slack of oxygen at a particular altitude. Extreme exercise must be avoided for at least 48 hours. 

What age group of people are more prone to get altitude sickness?

If you are dedicated then age is no fence to your success in those high altitudes. Men are indeed more prone to be affected by altitude sickness than women but there is no specific age group that we can consider in danger of altitude sickness. 

People who live at low altitudes are also at risk of altitude sickness during high-altitude treks. Because their body is not used to the high elevation. 

Similarly, people who previously had altitude sickness are also in the menace of suffering from altitude sickness. 

Being young, energetic, and fit doesn’t mean you are away from the risk factors of altitude sickness. Even the athlete also might suffer from altitude sickness. Different types of symptoms may arise while elevating to a higher altitude. So, you must always apply safety measures primarily. 

How long does Altitude sickness last?

Altitude sickness is sure a life threat but it is not incurable. After the symptoms start developing, the symptoms will slowly wear off within two to three days if you do proper rest and animalization and descend to a lower altitude. But if the case is severe and the symptoms have already developed to HAPE (High Altitude Pulmonary Edema) then it might take a week or a few more to clear up in the worst-case scenario hospitalization can be the right decision. 

Who should avoid high-altitude treks?

High altitude is not something to be taken lightly, so people with heart failure, sickle cell disease, myocardial ischemia, any form of pulmonary insufficiency or preexisting hypoxemia, or obstructive sleep apnea should seriously consult with a medical expert who is confidential to high altitude medicinal issues. 

Can high altitude affect your heart?

Severe exposure to altitude can affect our cardiovascular system. Because of low oxygen, it can lead to hypoxia. High-altitude trekking can put a lot of pressure on the heart and blood vessels due to low oxygen levels, we might witness a temporary increase in blood pressure until your body adapts to the altitude. 

Is it safe for pregnant women to travel to high altitudes?

According to obstetrics, women should not travel to an altitude above 2500m (8000 ft) above sea level during pregnancy. Because of low oxygen levels, the fetus inside the mother’s womb can develop a condition called hypoxia. 

Why are sherpas at low risk of Altitude sickness?

Sherpas are the Tibetan ethnic group, natives of the mountain region of Nepal. Sherpas are considered superhuman in the Himalayan region. Due to genetics and exposure to extremely cold temperatures, sherpas have already adapted to the cold climate. Their body is developed in such a way that they can easily digest that atmospheric pressure. Their body is capable of not producing a surplus of red blood cells in counter to the low oxygen like lowland people. Their body can produce more amount of nitric oxide, which is responsible for opening blood vessels to promote stronger blood flow. Which keeps them a lot more energetic than other normal people. 

Even though the build of their body is different than normal people’s, their performance at high altitudes is 30% better than that of normal people. They have a lot more capillaries per square centimeter of muscle. Their measurement of the chest is bigger and also have greater lung capacity. They even have a high measure of peak flow as well. Due to these reasons, the sherpas have outstanding performances in high altitudes and are known as superheroes of the mountain. 

What vitamins are helpful at high altitudes?

Scientifically it is proven that 1,000mg of vitamin C, 400 IU of vitamin E, and 600mg of Lipoic acid daily have notably improved the developing symptoms of altitude sickness. 

The complication of Altitude Sickness.

Altitude sickness is surely curable but if ignored and not recognized in early symptoms, it can develop into HAPE or HACE and certainly be life-threatening. The heart and brain are prime organs that are affected by altitude sickness. 

What is the insurance facility for Altitude Sickness?

Trekking at high altitudes can be quite risky so insurance is foremost. You must make sure the insurance company is covering up to the risks at an altitude of 6000 meters. We highly suggest you have insurance covering the helicopter evacuation fee as well. Because the sudden helicopter evacuation can be extremely expensive. 

There are many trustworthy insurance companies like World Nomad, which is very reliable. 

The region above 7000m is mentioned as a death zone. The death rate from altitude sickness is evaluated to be 4%. This means, that out of 1 lakh travelers, 14 people die in their journey due to altitude sickness. If you are traveling with a guide then you will always have assistants. Your safety is a lot more assured when you are with a guide other than traveling solo. So we highly recommend our guests to be very cautious and end the high-altitude trek on a very good note. 

About Author

Bikash is the youngest member of the company. He finished high school in 2020 and now studying bachelor's in travel and tourism major. Currently, he works as a content writer and prepares the best, creative and informative blogs and articles.
During his free time, he loves to travel, explore new places and learn new things.

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