High altitude sickness in Nepal
A Guide on Preventing High Altitude Sickness in Nepal

High Altitude Sickness in Nepal

High-altitude sickness, a challenging and rare clinical situation, is the result of an overly rapid ascent to an altitude that is not typically encountered in daily life.

Deepak Raj Bhatta
Author | Deepak Raj Bhatta Date Published:
altitude sickness in nepal

High Altitude Sickness is a common medical condition that arises when people ascend to altitudes greater than 2500 meters (8200 feet) without acclimatizing. Symptoms may include headache, nausea and vomiting, ear-popping noises, and swelling of the throat and face.

At any time during their stay at high altitude, the individuals may experience symptoms such as difficulty breathing; headache; nausea; shortness of breath; nausea or vomiting; dizziness or lightheadedness.

Symptoms vary depending on the individual's age and gender. The first signs individual experiences during their stay at high altitude are usually anxiety, headaches, dizziness, fatigue and tachycardia.

These symptoms are known as acute mountain sickness (AMS), which may be severe in some cases. The most severe cases require immediate descent and medical treatment.

The symptoms of AMS may be relieved by medication, rest and careful acclimatization. After a few days, the symptoms of AMS usually subside. At this time, the individual can begin a slower ascent towards higher altitudes to help prevent or reduce the severity of possible altitude sickness.

A previous history of AMS may make the treatment inadequate. It is important to consult with a high altitude physician. If AMS continues to be severe, treatment may include being brought down to lower altitudes and lying in a chamber for several days. The individual may be given oxygen, antibiotics and other medications depending on the symptoms and severity of altitude sickness.

Table Of Content

    What is Altitude Sickness?

    Altitude sickness is an illness that affects your body when you're at a high altitude. The atmospheric pressure at high altitude is what's referred to as the ‘barometric pressure’. The decrease in barometric pressure in the higher elevation stimulates the intensity of altitude sickness. A person can be affected by this illness, especially when they are sleeping or inactive. Also, the rapid gain of elevations in the mountains can be a cause of AMS. 

    There have been many theories about the cause of altitude sickness. It has been stated that there are numerous reasons for the cause of altitude sickness:

    • The person's inability to adjust with the decrease or increase of altitude.
    • The air is different, so it affects the body in a different way.
    • UV radiation, especially in high altitudes (above 10,000 feet).
    • The lower concentration of oxygen in high altitudes.
    • The person's respiratory system is not adjusted to the new speed of breathing.
    • The change in air pressure.
    • A decrease in body fluids causes an imbalance.
    • An improper diet causes a deficiency of vitamins, minerals, or electrolytes.
    • Personal habits such as smoking or drinking alcohol, and sleeping while at altitude. These habits could cause a number of problems with the body's ability to perform and function properly during altitude changes.
    • Some diseases can induce altitude sickness.
    • The body's weakened immunity after a previous infection.
    • Other sicknesses such as heart disease, lung disease, diabetes and obesity could all be risk factors for altitude sickness.

    Types of Altitude Sickness

    There are different levels of altitude sickness and most of them can be spotted early enough for proper treatment to occur.

    High Altitude Sickness is subcategorized into three parts for better understanding and the intensity of sickness according to the elevation gain. 

    Acute Mountain Sickness (AMS)

    Lacking acclimatization, it can be deadly to go hiking in the mountains. Acute Mountain Sickness is a severe form of mountain sickness that can occur when you're travelling at elevations above 8,000 feet and don't allow yourself time to acclimatize before entering the high mountain range. People who experience severe AMS typically become short of breath, dizzy, and disoriented. They may also have trouble sleeping, and some even experience convulsions.

    Many people believe that AMS is triggered when you move from sea level to an altitude of 8,000 feet. Unfortunately, this isn't true; AMS can be triggered by any altitude change. In fact, AMS has been experienced by hikers when they've left the mountain peak and descended nearly to the bottom. Once they reach the valley floor and begin to acclimatize before climbing back up, they're fine again.

    What Causes AMS? 

    The simple answer is that air pressure decreases with increasing altitude, thus decreasing your ability to oxygenate your blood until hypoxia occurs. Altitude sickness is caused by a number of factors. The first is that there are fewer oxygen molecules per breath at higher elevations. The second factor is, at higher altitudes, there is less available oxygen in the air and diminished amounts of iron content. This can cause tiredness and anemia.

    High Altitude Pulmonary Edema (HAPE)

    HAPE can be described as fluid build-up in the lungs which can eventually cause death. It is a complication of altitude sickness and it most commonly occurs in people traveling to high altitudes for recreational or tourism reasons. In addition to having symptoms such as shortness of breath, chest pain, cough, fatigue, and confusion, survivors may also experience acute pneumonia.

    High Altitude Pulmonary Edema (HAPE) is a serious medical emergency caused by the body's reaction to high altitude. HAPE can be treated before it becomes life-threatening, but it needs to be diagnosed early.

    Altitude sickness, also known as acute mountain sickness (AMS), is a condition in which people have trouble getting enough oxygen in the air at high altitudes. As you go higher in elevation, atmospheric pressure decreases and gasses in the air are thinner. The lower the temperature, the more common AMS is. The most common altitude sickness is called ‘High Altitude Pulmonary Edema’ (HAPE), which occurs when fluid seeps into the lungs.

    High-Altitude Pulmonary Edema is a kind of Edema that occurs in the lungs due to an increase in the amount of liquid produced by alveolar spongy lining tissue as a result of increased arterial pressure.

    While HAPE is similar to any other form of acute lung injury: it generally responds well to standard treatments such as positive pressure immobilization and oxygen therapy.

    Travellers are advised to undertake prevention measures before the ascent. There is no cure for HAPE, so the only option is to treat the symptoms, which typically involves hospitalization. While there is no cure for HAPE, it can be treated with oxygen and drugs that lessen the amount of fluid in the lungs. Symptoms will slowly improve after descending down to a lower altitude. 

    The initial symptoms of HAPE can often be confused with altitude sickness as they include nausea, difficulty sleeping, and fatigue.

    In addition, at high altitudes, low partial pressure of oxygen causes hypoxia. The combination of hypoxia and Edema contributes to increasing the thickness of the pulmonary vascular bed.

    Because HAPE has a high mortality rate, it is important that it be treated as soon as possible once symptoms appear. It is recommended that climbers ascend no more than 300 meters (984 feet) per day above 4000 meters (13123 ft) and take frequent acclimatization that is enough for the body to adjust to the rapidly changing elevations. 

    The cause of HAPE is related to the reduction in atmospheric pressure that occurs as altitude increases.

    High Altitude Cerebral Edema (HACE)

    High Altitude Cerebral Edema (HACE) is a high-altitude sickness that results in the build-up of fluid in the brain. This condition can happen with high elevation climbing and mountain hiking but is most often experienced during commercial airline trips.

    HACE presents itself with confusion, nausea, and vomiting within 24 hours of reaching altitude, passing out or being unable to walk due to worsening headaches. If one continues to feel ill and passes out, he or she is said to have died from HACE. If HACE is severe enough, it can lead to death. The symptoms of HACE are very similar to the symptoms of altitude sickness.

    HACE is a result of fluid pressure on brain cells (which can cause depression and confusion), and signs of developing brain Edema (such as increased intracranial pressure). In most cases, HACE is not life-threatening, but there are some risk factors that can cause severe or fatal outcomes if left untreated. A few of these include rapid ascent to altitude and increased body mass. 

    HACE is commonly experienced by mountain climbers. In most severe cases, it takes life due to unconsciousness and increasing fluid pressure on the brain. The chances of HACE are high in the elevations above 5500 m. So, the risk of HACE is elevated with the elevation gain in the Himalayas.

    High Altitude Sickness while trekking in Nepal

    Trekking in Nepal comes with an incredible adventure and mind-blowing Himalayan experience. Most of the trekking areas of Nepal lie in the mountain region that is above 2000 m. Getting to the high mountain areas poses a significant risk of altitude sickness in Nepal. 

    While trekking in the mountains, the elevation changes. As you gain elevation, the density of oxygen in the atmosphere decreases making it difficult to adapt to the new atmosphere. The difficulty caused due to the elevation gain is altitude sickness. Nepal is a country with diverse landscapes and geography. Most of the country is mountains and the Himalayas. Many people, every year, come to visit the mountains of Nepal. And altitude sickness is the common term while trekking in the higher elevations. 

    Mostly, people start to experience sickness above 3500 m. in the mountains of Nepal. But with proper acclimatization and overstays during the trek, the risk of sickness can be mitigated. 

    The altitude sickness below 4000 m. is mild and with proper acclimatization, hydration and medication can be cured. The sickness above 4000 m. needs a little extra acclimatization stay, medication, proper diet and in some cases evacuation and medical assistance. 

    Altitude Sickness in Everest Region

    Everest region is known for its awe-inspiring beauty and incredible mountain panoramas in eastern Nepal. It is also one of the most visited trekking areas of Nepal and home to the highest eight-thousander in the world. Getting to the various places is not that easy as it requires tremendous preparation, time and physical ability. Since it lies in the higher elevation, i.e. beyond 10,000 ft. altitude sickness is frequent for travellers. Trekking to the Everest Base Camp is moderately difficult but the difficult terrains and high altitude makes it demanding in terms of personal care. 

    If you are trekking in the higher areas of the Khumbu region, getting prepared by taking enough acclimatization along the trek can help you avoid or lessen the risk of mountain sickness. Also, gaining elevation rapidly in the mountains increases the risk of AMS and it can be life-threatening. If you experience mild sickness, with some acclimatization, proper diet and medication, it should go away. But if you experience a severe form of mountain sickness, losing altitude and getting Heli evacuation to the medical facility is advised.

    While trekking in the Everest area, obtaining Insurance helps you a lot in case of uncertainties. So, obtain insurance, get a guide, and gather information on the type of precautions you should take while getting higher in the mountains. For more information on the difficulty in the Everest Base Camp, visit How Difficult is Everest Base Camp Trek.


    Altitude Sickness in Annapurna Region

    Annapurna region is known for its cultural and natural attractions. Trekking is one of the most admired activities in the Annapurna area of Nepal. As a matter of fact, getting in any mountains that are higher in elevation poses a risk of Mountain sickness. The only cure that can help to mitigate the risk of AMS is acclimatization. Mountain sickness cannot be prevented completely as it’s the atmosphere that plays a role in it but the risk can be lowered with proper care and a few precautions. The base camp of the mountains and elevations above 3500 m. are high Prone zones to AMS.

    Annapurna mountain area is most vivid and incredibly filled with mind-blowing natural beauty. So, Annapurna is the trekker’s top choice and a place that relinquishes the unworthiness and showers the soul with its spiritual Himalayan atmosphere. While trekking in the lower parts of Annapurna, the risk of AMS is low if you have spent a few days in Kathmandu and Pokhara. But the sudden rise in the higher elevations might cause you nausea, swelling and jeopardize your adventure with altitude sickness.

    How to Prevent High Altitude Sickness while trekking in Nepal?

    Preventing altitude sickness is important but at the same time, complete prevention of AMS is impossible. We can lower the risk by taking a few health measures and supplements, but we cannot prevent something that is in the atmosphere. Some of the health measures that we can take while trekking in the higher elevations of Nepal are:- 

    • Don’t prevent, understand and adapt to the nature of mountains. 
    • Slow elevation gain and acclimatization is the key. 
    • Have patience, don’t push yourself to exhaustion. 
    • Stay hydrated, motivated and fueled. 
    • Don’t drink and Smoke. 
    • Get some herbal tea, use warm water, and wear comfortable clothes. 
    • Use medications (eg. Diamox), in case of altitude sickness. Having a prescription from your consultant is important if you have any allergic and adverse reactive factors. 
    • If you observe severe AMS, immediately get to the lower elevations. 
    • Consult your physician, if possible. 
    • Acclimatize. And if it still doesn’t work, request a Heli evacuation to a medical facility. 

    Frequently Asked Questions

    • Can you get altitude sickness in Kathmandu?

      Yes, it is possible but a rare chance. If you are travelling from sea level to Kathmandu, the chances of AMS are there. But many people do not experience AMS in Kathmandu alone. Kathmandu is a city that sits at an elevation of 1400 m. above sea level. This level of elevation is adaptable for most people. 

    • How high do you have to be to get altitude sickness?

      Mostly, the risk of AMS increases once you start ascending above 2500 m above sea level. In generic terms, if you are ascending elevation above your usual climate, there is a chance, maybe rare, but you might experience altitude sickness. So, it is important to gain elevation gently and with proper acclimatization to ensure that you adapt to the new atmosphere. 

    • What is the fastest way to adjust to altitude?

      There is no fastest way to adjust it. But you can lose elevation to mitigate the altitude sickness, or just take some medication to cope if it's not severe. In case of severe sickness, heli evacuation is very important. Severe Altitude Sickness can be life-threatening and poses a significant risk to the health. 

      A quick way to lower the mild AMS, if you experience it, is to hike down the lower elevation. This technique is mostly used by mountaineers where they ascend the elevation and descend to the lower areas. It is important in most cases as it helps you acclimatize. 

    • What foods help with altitude sickness?

      A healthy meal that has some calories and a balanced diet that is a rich source of energy is important. You will be continuously trekking in the mountains, so a proper diet is very important. Rice, Daal, Bhaat, lentils, green veggies, eggs, energizers and sufficient healthy fluid and water are some important foods to take in the mountains.

    • How many days will it take your body to fully adapt to a high altitude environment?

      Usually, your body can adapt to the new elevation in one to two days (up to 5000 m.). It may take up to four days for some people to get used to the new environment. 

    • Is there reverse altitude sickness?

      The potential of reverse altitude sickness is very rare. However, a few people might experience reverse altitude sickness if they have spent some long time in the higher elevation and quickly get back to sea level. This syndrome is also known as a high-altitude de-acclimatisation syndrome (HADAS) and is adaptable by the body. 

    • How do you prepare your body for high altitudes?

      Some exercise, regular hiking around the hills, and acclimatization during the trek should work for high elevations. But mountains are the most unpredictable yet incredibly beautiful places to be. So, the chance of AMS is there despite all the measures, in such cases, seek Heli evacuation and emergency help. 


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