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Everest Base Camp Altitude Sickness



Introduction to Everest Base Camp Altitude Sickness

Everest Base Camp Trek (EBC trek), a thrilling adventure trek, attracts numerous trekkers every year. Located in the Khumbu Region of Nepal, the trek is well-known for its astonishing scenery, picturesque village, and its proximity to the world’s highest peak – Mt. Everest (8848.86 meters). EBC trek covers roughly 130 kilometers, making it one of the top trek among Nepal’s top 10 trekking destinations. Throughout the trek, trekkers navigate through all sorts of terrains, traverse suspension bridges, and experience various climatic conditions. The trek to EBC is not everyone’s cup of tea, it requires physical fitness, mental readiness, and well-equipped gear and supplies. It involves significant challenges, necessitating thorough planning, sufficient acclimatization, and profound respect for the environment, or one might fall victim to altitude sickness and other life-threatening dangers such as avalanches and landslides, isolation and communication problems, animal encounters, and many more.

Altitude sickness or Acute Mountain Sickness (AMS), is a condition that the body experiences when it cannot adjust to the reduced oxygen levels at higher regions on the globe. Altitude sickness in Everest Base Camp (EBC, at an altitude of 5364 meters) is a common concern for trekkers, as well as many other high-altitude treks (typically above 2500 meters). As the body struggles to adapt to the reduced oxygen levels, it might lead to a range of symptoms from mild headaches to severe, life-threatening dangers while trekking to Everest Base Camp. This article is an accumulation of the causes, symptoms, prevention, and treatment of altitude sickness while trekking to Everest Base Camp. (Trekking Planner (P.) Ltd, 2023)

Types and Symptoms of Altitude Sickness during EBC Trek

Altitude sickness or altitude sickness in Mount Everest is generally classified into three categories: acute mountain sickness (AMS), high-altitude pulmonary edema (HAPE), and high-altitude cerebral edema (HACE).

Acute Motion Sickness (AMS) at EBC Trek

Acute Motion Sickness (AMS) is a type of altitude sickness that the body experiences when one of our sensory organs that is responsible for balancing such as the inner ears, eyes, and sensory nerves feels that our body is not in balance or moving while other senses feel that our body is stationary. It is mild in nature. The person suffering from AMS on Mt. Everest includes symptoms such as headache, nausea, dizziness, fatigue, shortness of breath, loss of appetite, and difficulty sleeping. These symptoms are similar to a hangover and generally last for a few hours to a day after arrival at a high altitude.

High Altitude Pulmonary Edema (HAPE) at EBC Trek

High Altitude Pulmonary Edema (HAPE) is a dangerous condition where the formation of fluids occurs. This fluid prevents the filling of new and fresh oxygen in the lungs. Due to lack of fresh oxygen, maintaining energy in the body becomes extremely difficult, even walking and carrying light objects becomes challenging. It usually occurs at a very high altitude, that is, above 3,500 meters (such as Everest base camp). A person suffering from HAPE includes symptoms such as extreme shortness of breath, a feeling of suffocation, chest tightness, and a persistent cough producing frothy or bloody sputum. If not treated immediately, it could be fatal. Ones who have previously experienced HAPE are more susceptible to developing it again.

High Altitude Cerebral Edema (HACE) at EBC Trek

High Altitude Cerebral Edema (HACE), is a severe and life-threatening condition of altitude sickness, caused due to accumulation of fluid in the brain. HACE involves swelling of the brain, hallucination, confusion, inability to think clearly, severe headache, loss of coordination, and, if left untreated, coma. HACE typically develops after prolonged exposure to high altitude and can be fatal within 24 hours if not treated promptly. Mere 1% of people who ascend beyond 3000 meters or extremely high altitude (above 5,550m) experience HACE. The quicker people ascend the mountains without acclimatizing properly to the altitude such as during high altitude trek to Everest base camp, the higher the risk of developing HACE. (Trek Route, 2018)

Understanding Altitude Sickness on Everest

Causes of Altitude Sicknesses on Everest

When the body is unable to acclimatize to the reduced to the reduced oxygen level as we ascend to higher altitude, one can experience altitude sickness. With the increase in altitude during the trek to the highest mountain in the world, the air pressure decreases making the availability of oxygen scarce. To compensate for the insufficient oxygen level in the lungs, the body starts to increase the breathing rate and heart rate, causing the leak of fluid from the capillaries, resulting in symptoms of altitude sickness. The severity of altitude sickness at Everest Base Camp can equally be triggered by the following factors:

  1. Rapid ascend and altitude reached
  2. Overexertion within 24 hours of ascent
  3. Insufficient fluid intake
  4. Hypothermia
  5. Consumption of sedatives or alcohol
  6. Individual physical and mental health and many more. (Bhusal, 2022)

Preventing Altitude Sickness on Everest

Gradual Ascent

A great way to prevent altitude sickness is to take it slow when ascending. The body needs to get habitual with the decrease in oxygen level with the increasing altitude of Mount Everest. It is generally advised not to ascend more than 300 – 500 meters (1000 – 1600 feet) per day above 3000 meters (9800 feet). The inclusion of rest days during the EBC trek allows the body to get acclimatized properly to its new environment. Itineraries for the Everest Base Camp trip include several acclimatization days in locations like Namche Bazaar and Dingboche.

Hydration and Nutrition

At high altitudes like EBC, thin air pulls moisture from your body, making dehydration a significant risk factor for altitude sickness. So, staying well-hydrated should be prioritized. Trekkers are advised not to drink chilled water but to drink warm water (at least 2 – 3 liters per day) even if they don’t feel thirsty. It is recommended to drink 500 ml of water every half-hour’s trek. While it’s common to lose appetite at high altitudes, the body actually burns more energy during a trek. To counter this, opt for easily digestible, high-calorie liquid foods that are available around Mt. Everest throughout the hike to keep energy levels up and avoid an empty stomach.


Acetazolamide (Diamox) is commonly prescribed to prevent and reduce the symptoms of AMS. It works by acidifying the blood, which stimulates breathing and helps increase oxygen levels. Dexamethasone, a steroid, can be used to prevent and treat HACE. However, these medications should be used under medical supervision and are not substitutes for proper acclimatization. These medicines might not be readily available when trekking to EBC. So, we need to see if it’s available or not.

Physical and Mental Fitness

Physical fitness itself does not prevent altitude sickness, but being in good physical condition can help trekkers handle the physical demands of the trek better. However, it’s important to note that even the fittest individuals can suffer from altitude sickness. Similarly, psychological factors can lead to falling ill. So, be confident and mentally prepared for any difficulties that one might encounter on EBC. Avoiding negative thoughts or emerging in the serene beauty of Mount Everest and its beautiful atmosphere and finding enjoyment in the company of fellow trekkers might be a change in environment. (Crockford, 2020)

Avoid Alcohol and Smoking

As we move towards higher altitudes, the air gets thinner. Alcohol dehydrates our body and smoking reduces blood oxygen levels, both of which can cause or worsen altitude sickness. A moderate amount of alcohol or smoking consumption is acceptable on our way back to lower altitudes. (Subedi, 2018)

Recognizing and Responding to Altitude Sickness on Everest

Early Recognition

Recognition of early symptoms of altitude sickness on Everest Base Camp is important for preventing it from becoming severe. Trekkers should be aware of their body’s limits and their companions’ health, looking out for symptoms like headaches, nausea, dizziness, and unusual fatigue. Keeping a close eye on is essential, especially during the night when things could worsen.

Immediate Actions

If symptoms of altitude sickness appear during ascending EBC, the first response should be to stop ascending and rest. Mild symptoms can often be treated by taking a rest day, hydrating, and eating well. If symptoms persist or worsen, descending to a lower altitude is the most effective treatment. In cases of severe altitude sickness (HACE or HAPE), immediate descent is critical, and supplemental oxygen or medication may be necessary.

Emergency Response

In severe cases, evacuation may be necessary. Trekkers should be prepared for emergencies by knowing the locations of the nearest medical facilities and having access to emergency communication methods. Many trekking companies provide guides who are trained in altitude sickness management and can assist in emergencies.

Also, if anyone falls victim to AMS during the EBC trek and is unable to walk back down to a lower and safe altitude, then evacuation through a helicopter could be the best option. In the case of the EBC trek, helicopter evacuation will be organized by the trek guide. However, it is to be noted that helicopter evacuation is extremely expensive, so everyone could not afford it. It’s therefore important to be well-equipped in case of any emergencies. (Follow Alice, 2022)

Understanding Acclimatization at EBC

Acclimatization is the key to a safe Everest Base Camp trek. It allows your body to gradually adjust to the decreasing oxygen levels. Here are some effective acclimatization strategies:

  1. Trekking Itinerary: Choose a trek itinerary that integrates acclimatization days. These involve shorter hikes or rest stops at higher elevations, giving your body crucial time to produce more red blood cells for optimal oxygen transportation. A well-designed itinerary, like a 14-day trek, balances ascent with rest to facilitate acclimatization.
  2. Gradual Ascend: Resist the urge to reach higher altitudes quickly. Ascend gradually, taking breaks every few hundred meters. This allows your body to continuously adapt to the thinning air.
  3. Climb High, Sleep Low: This strategy involves hiking to a higher altitude during the day and then descending to sleep at a lower altitude. This exposes your body to the challenge of higher altitude during the day and allows for better recovery during sleep at a lower altitude with more oxygen.

How many itinerary days to trek to Everest Base Camp?

The number of itinerary days to Everest Base Camp can vary individually. Some might recommend an itinerary of 12 days, whereas some might recommend 18 to 20 days. Likewise, few experienced trekkers and well-known for the route and environment to EBC might finish the trek in less than 12 days. However, it is recommended by most of the trekkers to keep 14 14-day itinerary, and maybe more than 14 days for the new trekkers. More itinerary days provide trekkers enough days to rest and acclimatize to the high altitude.

Here’s a breakdown of the 14-day itinerary to Everest Base camp

  • Day 1 – Fly to Lukla (2,840m), trek to Phakding (2,610m)
  • Day 2 – Trek to Namche Bazaar (3,440m)
  • Day 3 – Acclimatizing Day 1
  • Day 4 – Trek to Tengboche (3,860m)
  • Day 5 – Trek to Pangboche (3,930m) [Extra day as compared to 12-day itinerary]
  • Day 6 – Acclimatizing Day 2 [Extra day as compared to 12-day itinerary]
  • Day 7 – Trek to Dingboche (4,410m)
  • Day 8  – Acclimatizing Day 3
  • Day 9 – Trek to Lobuche (4,931m)
  • Day 10 – Trek to Gorakshep(5,200m), afternoon to Everest Base Camp
  • Day 11 – Ascend Kala Patar (5,545m) and return to Pheriche
  • Day 12 – Trek back to Phortse village (3,800m)
  • Day 13 – Trek back to Monjo (2,610m)
  • Day 14 – Trek back to Lukla (2,840m) (Hunter, 2021)

Personal Experiences and Lessons of Altitude Sickness at EBC

Case Studies

Numerous trekkers have shared their personal experiences with altitude sickness on the Everest Base Camp trek. These stories highlight the unpredictability of altitude sickness and the importance of proper acclimatization and precautionary measures. For instance, when discussing dangers at the EBC trek, one trekker shared their experience of developing severe AMS symptoms despite being physically fit and well-prepared, emphasizing the need to listen to one’s body and not push through symptoms. A doctor’s consultation beforehand to assess one’s suitability for high-altitude travel has been highly recommended.

Lessons Learned

The key lessons from personal experiences from the Everest Base Camp trek include the importance of gradual ascent, staying hydrated, eating well, and not ignoring symptoms. Many trekkers advise against the use of alcohol and recommend taking rest days seriously. Understanding that altitude sickness can affect anyone, regardless of fitness level, and being prepared to turn back if necessary, are crucial takeaways. Remember, conquering Everest Base Camp is a marathon, not a sprint; pace yourself and listen to your body for a successful and enjoyable trek.


Everest Base Camp Trek is an exhilarating adventure, but altitude sickness poses a significant health risk.  Understanding its symptoms and implementing effective acclimatization strategies are vital. Following preventive measures like gradual ascent, staying hydrated, proper nutrition, and use of medication could be a life-saver. Recognizing the signs of altitude sickness and being mentally and physically prepared are essential strategies for preventing and managing altitude sickness. Trekkers must prioritize their health and safety, understanding that reaching Everest Base Camp is an achievement, but not at the cost of their well-being. By prioritizing careful planning and respect for the body’s limits, the trek to Everest Base Camp can be a safe and unforgettable adventure.

About Shobita Neupane

Shobita is a co-founder of Travel Diary Nepal. She is a passionate traveler and a content writer. Her favorite quote is Fly so high until your problem looks smaller and the dream seems closer.

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