How to Prevent Altitude Sickness on Everest Base Camp Trek

How to Prevent Altitude Sickness on Everest Base Camp Trek

The stories of people conquering the summit of Mt. Everest or the Everest base camp stir the hearts of adventure seekers with awe, excitement, and a wish to be a part of the elite climbers. From time to time, there is also devastating news about people suffering from Altitude sickness or even losing their lives on these expeditions. While the majestic beauty and grandeur of the Himalayas cannot be denied, it is equally important to realize the dangers and challenges. The climbers and trekkers have to face and ways to prevent Altitude sickness on Everest Base camp Trek.

Altitude sickness has been one of the deadly challenges faced by all the trekkers who embark on their exciting journeys to Mount Everest, the highest peak in the world. Hundreds have to halt their journeys and some even lose their lives due to this mountain disaster. So here we present you a comprehensive guide to Altitude sickness, its signs and symptoms and ways to prevent it in EBC so you have a fun, exciting and successful experience.

So, What is Altitude Sickness?

Altitude sickness is a pathological effect of high elevation on the human body that ranges from mild symptoms to mortality. Also known as acute mountain sickness (AMS) and hypobaropathy, it is a condition that starts affecting people from the elevation of 2400meters. As trekkers ascend the trails, the cold, sun, wind, and low oxygen level (60% less than sea level) make the trekking more challenging. The body starts suffering from different weaknesses and conditions like nausea, diarrhea, and insomnia to more severe ones that could be fatal.

Altitude sickness on Everest Base Camp Trek is caused by the rate of ascending more than the altitude itself. It can affect people irrespective of their age, sex, physical and medical conditions. As people are traveling to high altitude destinations for adventures such as trekking, mountain climbing, skiing, and skydiving, cases of altitude sickness are becoming more common. Lack of knowledge, ignorance or the habit of overestimating one’s abilities has been the major cause of altitude sickness among trekkers who visit the Khumbu region.

Signs and Symptoms of Altitude Sickness

While some people feel the effects of altitude sickness as soon as they ascend to a higher elevation, it can also take 5 to 7 hours for the symptoms to appear for others. Most people feel the symptoms during or after sleep. Here are the first and minor signs of altitude sickness on Everest Base Camp Trek.

  • Headache
  • Lethargy
  • Insomnia
  • Nausea
  • Lack of coordination
  • Loss of appetite
  • Swelling of hands and feet
  • Excessive flatulence

If these are ignored and no measures are taken, the condition gets worse with the following effects

  • Irrational behavior and depression
  • Lack of performance (no walking coordination)
  • Breathlessness
  • Heart palpitation
  • Coughing with frothy or bloody sputum

It is important to be aware of these, take rest and ask for medical assistance as soon as the common symptoms appear. If left untreated, the symptoms could develop into serious conditions such as


High altitude pulmonary edema is a condition where the lungs get filled with fluid as the body tries to maintain the breathing rate and dehydration by releasing water from the lungs. It can be cured by descending to lower elevations.


High altitude cerebral edema is the condition when there is an accumulation of blood in the brain as it tries to adjust to the lowering oxygen levels. First, the person becomes uncoordinated, then slowly goes into a coma and might even lose their life. Dexamethasone can delay the symptoms while descend is the only cure for this condition.

Types of Altitude Sickness on Everest Base Camp Trek

There are three types of altitude sickness based on the level of elevation they occur in.

High altitude/Acute sickness

This occurs at the altitude of 3000 meters or higher that only causes mild symptoms like nausea, headache, loss of appetite, and dizziness.

Very high/moderate altitude sickness

It occurs at an altitude of more than 5000m. There are problems in co-ordination and medicines are ineffective to reduce other symptoms. If trekkers are unable to walk straight, evacuation is a must.

Extremely high/Severe altitude sickness

It occurs at around 6000m or more with severe conditions like fluid buildup, physical imbalance, fainting, or even coma. In such cases, immediate descent and medical treatment are required.

How to Prevent Altitude sickness on Everest Base Camp Trek?

How to Prevent Altitude Sickness on Everest Base Camp Trek

Get Informed

The most important requisite for any high altitude trip is to do proper research and gain as much information (about the place, people, challenges and dangers of the trip) as possible. Most of the trekkers consider Everest base camp trek to be just another trek that they can easily handle. People also underestimate the altitude if they are from other high altitude places. EBC trek is a very challenging trek and the oxygen levels at the different points in the trail vary at different times and situations.

During colder months and snowstorms, the levels drop unexpectedly and even the most experienced people fall prey to the sickness. There is no other way but to learn about the altitude sickness on Everest Base Camp Trek, its symptoms, causes and preventive and curative measures. You can get information from websites, blogs, forums, travel agencies, other trekkers and many other sources. Having enough information and knowing the right steps to take at different stages of the trek can ensure a safe and successful trip.


Medicines like Diamox (Acetazolamide) have been proven to prevent altitude sickness to some extent as they speed up the acclimatization process. Taking the correct medicine with the right dosage means you can actually enjoy and complete the trek normally and successfully.

Slow pace

The major cause of Altitude sickness is people trying to finish their expedition as fast as possible. People tend to ignore the guidelines and overestimate their capabilities when it comes to such treks. Such hurried pace does not provide enough time and energy for the body to cope with the diminishing oxygen levels.

Every trekker, guide, and medical practitioner would advise you to take your time. Create a slow pace with proper rests and breathe normally. There is no hurry as one of the trekking guides or porters will always stay back with you to complete your expedition. Remember it is not a race, and the more important goal is to get to the base camp and return successfully and alive!

Climb High, Sleep Low

The effects of altitude sickness are most obvious and severe while sleeping. Most of your time is spent sleeping as you need proper rest during treks. This is when most of the symptoms of altitude sickness appear and people usually complain about the effects after waking up.

The way to prevent this effect is to climb high during the day and then return back a little to sleep at lower elevations. Above 3000m, the sleeping elevations should not increase more than 300m to 500m every day. At some places or some days, these elevations are higher than normal and are compensated by taking an extra rest day at such points. Such precaution ensures that the body adapts to the elevations during sleep and is ready for the assault of the next day.

Keep Hydrated

The long hours of trekking combined with the strains of the high elevation replenishes a lot of energy and dehydrates the body. The weakness can make the body susceptible to altitude sickness. Trekkers are suggested to drink up to 5 liters of water every day to maintain normal body conditions.

Avoid Alcohol and Smoking

Consumption of alcohol and smoking in the high altitude has even worse effects on the body than normal. They dehydrate the body, affect respiration, and other metabolic activities that weaken the body and lead to altitude sickness.


Altitude sickness affects people of all ages, physical, and medical conditions. Even the same person might have different experiences while completing the same trek. However, many trekkers with prior training and trekking experiences are reported to suffer less than those who have none. It is a good idea to trek around the hills and mountains of your own locality to get acquainted with trekking techniques and allow the body to adapt to thin air. So, go on high altitude treks in your hometown (around 3000m) so the body learns how to adapt to the thinning air at base camp at 5364m.

Know Your Limits

Most of the time, trekkers suffer because they ignore the symptoms or misread their conditions.  If you have any previous medical conditions, weaknesses, or altitude sickness experience, it means you are more likely to be affected. It is a good idea to pre-inform your guide or fellow trekkers about your condition. It is equally important to know how much you can push yourself. At the first signs of sickness, you can inform your team and rest or take the necessary precautions. While others might be there to cure it, you are the only one who can prevent it!

Try Cocoa

Another recommendation is taking dark chocolate on high altitude treks. It is believed that chewing cocoa in high elevations helped Native Americans to prevent altitude sickness during the mountain trips.

Use Pulse-Oximeters

Hand-held pulse oximeters can also be helpful to detect the effects of altitude sickness. Though the readings and results might not be accurate due to changes in breathing patterns, it can be used to confirm the symptoms of altitude sickness.

Don’t Lie

Most of the trekkers who suffer usually are the ones in large groups. Out of insecurity or shame, people tend to hide their symptoms and keep ascending as they do not want to affect the trip for the entire group. Such groupthink makes people lie to others and themselves about the sickness until it gets too far and critical. Do not lie to others or yourself about the symptoms. It is not a matter of affecting the trip or being ashamed of your condition. Altitude sickness on Everest Base Camp Trek is a normal condition that could affect anyone, anywhere at high elevation. So, inform others at the slightest feeling of unease to avoid the problem from getting worse.

Choose the Right Agency

There are a number of agencies to choose from and each one claims to be the best. Do your research and find the one with not just the success rate but also the safety guidelines. Find itineraries that have a relaxed approach to the destination and provide flexibility in case you need to rest and acclimatize.

Many agencies have short itineraries to complete the trek quick and earn fast. EBC is not a race but rather a beautiful journey that you need to enjoy and safely complete. Pick the travel agency with the right contacts and approach, agents who are dedicated to your well-being. Talk to the guides, porters, and other staff about how they would handle each emergency. You have to pay a huge amount for the trip, make sure you get the best out of every penny!

About Author

Mukti is is the founder and CEO of Himalayas on Foot. He started Himalayas on Foot in 2008 after working as a trekking porter, guide and then a sales manager for a decade.

He has done most of the treks in Nepal such as Everest Base Camp, Annapurna Base Camp, Manaslu Circuit Trek, Poon Hill, Langtang Trek, Annapurna Circuit, etc. Apart from Nepal, he has also travelled to Japan, Thailand, Malaysia, Hong Kong, China, Finland, Norway, Germany, Belgium, France and USA.

Mukti was also secretary of Trekking Agency Association of Nepal (TAAN) for the year 2015-2017. TAAN is an umbrella association of trekking agencies in the Nepal.

He speaks fluent English, Japanese and Nepali.

Mukti is friendly and he is the one who answers most of your trip questions. So if you have any inquiry about our trip, don't be shy. Write to us.

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