Altitude sickness causes and prevention

Altitude sickness, or mountain sickness, is a group of symptoms that a person can experience when they walk or climb to higher elevations too fast, without providing the body enough time to adjust. 

Causes of altitude sickness

The root cause of altitude sickness is atmospheric pressure (barometric pressure). At higher altitudes, the atmospheric pressure is less, and there is less oxygen in the air, which results in altitude sickness. 

However, if you live at higher altitudes, the body gets used to the air pressure and oxygen levels, so you will not catch altitude sickness.  

Every time you elevate more than 2,500m (8202ft), your risk of altitude sickness increases. 

Acute altitude sickness risk increases if you:

  • do not give time for proper acclimatization
  • ascend too quickly
  • have other sensitive medical problems such as heart, lung, or nervous system diseases
  • live near sea level and travel to higher altitudes
  • take alcohol during acclimatizing


What happens to your body at high altitudes?

As soon as you climb to a higher altitude, your body responds by trying to take in more oxygen from the air by increasing your breathing, which increases your metabolism.

Similarly, at higher altitudes, water loss increases, dehydrating you. Altitude sickness also suppresses your appetite even though your metabolism increases. It means you need to eat more than the amount you would like to eat.  

However, if you stay for days or weeks in high altitudes, your breathing increases, and the hemoglobin (a protein that carries oxygen in the blood) count in blood increases, and this is how you adjust to high altitudes.

Way to Everest 

What are the symptoms of altitude sickness?

Altitude Sickness symptoms vary based on how rigorously you are affected. The symptoms can be mild to severe, even life-threatening.

Here are the mild symptoms.

  • fatigue
  • headache
  • difficulty sleeping
  • dizziness
  • vomiting or nausea
  • appetite loss
  • Rapid heart rate (pulse)
  • Shortness of breath


Here are severe altitude sickness symptoms.

  • Cyanosis (Skin turns blue)
  • Congestion or chest tightness
  • Cough
  • Confusion
  • Blood on cough
  • Withdrawal from social interaction
  • Decreased consciousness
  • Shortness of breath at rest
  • Inability to walk altogether or inability to walk in a straight line
  • Pale or gray complexion


Types of mountain sickness

Based on symptoms and gravity of altitude sickness, there are three levels.

Acute mountain sickness (AMS)
It is the mildest and most common form of altitude sickness. The symptoms include hangover, dizziness, headache, nausea, and muscle aches.

High-altitude pulmonary edema (HAPE)
In this type of altitude sickness, there is fluid buildup in the lungs, which is quite dangerous. HAPE is the main cause of altitude sickness deaths, and its symptoms include a blue tinge to lips and skin, breathing difficulties, persistent cough, tiredness, and weakness. If you notice such symptoms, you need to descend immediately and take nifedipine and bottled oxygen if available. 

High-altitude cerebral edema (HACE)
It is the most severe form of altitude sickness characterized by fluid buildup in the brain. HACE is life-threatening, so it requires urgent medical care. Watch out for symptoms - feeling confused, loss of coordination, and hallucinations. To combat HACE, you need to move down to a lower altitude, take dexamethasone, and bottled oxygen if possible.


How do I avoid getting altitude sickness?

Acclimatization is the best method to prevent altitude sickness. As you climb higher, your lungs adjust by taking in more deep breaths that allow red blood cells to carry more oxygen to the body.

Here are some things you need to pay attention to avoid altitude sickness.

  • Please start your journey below 10,000ft. If you are flying or driving, spend a day at a destination below 10,000ft.
  • It is best to prepare yourself for high-altitude treks by taking part in stamina-building exercises a few weeks before starting your hike. 
  • If you have no time for proper acclimatization, you can use acetazolamide.
  • Climb high, sleep low. If you climb more than 1,000ft per day, you must descend to spend the night. 
  • Walk at your own pace.
  • Drink lots of water, more than 4 liters. Take plenty of liquids, especially garlic soup. 
  • Eat plenty of carbohydrates.
  • Avoid tobacco, alcohol, or certain medications such as sleeping pills. 
  • After initial 10,000ft, elevate only 1,000ft per day.
  • For every 3,000ft you climb, you need to acclimatize for a day.
  • If you become aware of symptoms of altitude sickness, you need to descend immediately. 


Are there any herbal remedies or medications that help you prevent altitude sickness?

Here are some ways you can prevent, if not reduce symptoms of altitude sickness.

Eat garlic and cloves.

Garlic thins blood vessels and enhances the blood flow in your body. Cloves also act similarly.

Use ibuprofen for headaches.
Headache is a common altitude sickness symptom. To combat a headache, you can use ibuprofen - a nonsteroidal painkiller.

Take Acetazolamide (Diamox)
Acetazolamide is a common medication that treats altitude sickness by decreasing nausea, dizziness, headaches, tiredness, and shortness of breath.

Drink lemon juice and cinnamon
Cinnamon soothes stomach muscles and is effective in preventing nausea and vomiting. Lemon juice will reduce vomiting, fever, coughs, and headache.


Who is at risk?

Altitude sickness can strike anytime, anyone, even Olympic athletes. So, you cannot be sure, even fit, young and healthy people can get altitude sickness.

However, the chance of catching altitude sickness depends on factors like elevation, ascending rate, and at what altitude you sleep. 

People with medical conditions such as sickle cell anemia, pregnancy, heart failure, unstable angina, or cystic fibrosis are more prone to altitude sickness symptoms.


Treating mountain sickness

If you have mild symptoms, you can stay in the current elevation and see if the body adapts. 

However, if your symptoms do not disappear, you need to get to lower elevations. There is no point in exerting yourself.

Travellers catching a breath near by Annapurna Base Camp

If your symptoms are severe, your doctor will look for signs of fluid accumulation in your chest with an X-ray or stethoscope or use a CT scan to look for fluid in your brain.

If you have High-altitude pulmonary edema (HAPE), you might need supplemental oxygen, and in the case of High-altitude cerebral edema (HACE), your doctor might give you dexamethasone.


Precautions Discovery World Trekking takes against altitude sickness.

As a responsible trek and tour company, we take the following precautions to safeguard you from altitude sickness.

Experienced & trained crew

Our crew members come from the remote Himalayas, and they have been conducting remote high Himalaya treks for a long time. They can evaluate the situation correctly and take appropriate action, including deploying a helicopter to bring seriously affected persons back to safety. In addition, our trek crew members have completed intensive wilderness first aid training.

Discovery World Trekking head office remains in contact with all its trekking groups, at least once a day, through mobile to ensure that the treks are progressing as planned. In an emergency, your trek guide will contact the head office and decide how to handle any situation that may arise due to altitude sickness.

Mental support
If you are mentally strong, you can mitigate the effects of altitude sickness. Our crew members will be there along with you cheering you, lifting your spirits, and motivating you for your successful high altitude trek. If you trek with us, we ensure that you remain stress-free throughout your journey. 

Family-like Care
We treat each of our valuable clients as a member of our extended global family and pay attention to your health and safety. With us, you will always feel cared for and get the attention you need. We will provide you with enough hygienic and nutritious food to help you avoid altitude sickness.

These are a few reasons our trek success rate is more than 90%.


Planning your next trip

Discovery World Trekking designs its trek/climbing packages paying great attention to preventing altitude sickness. In addition, our teams carry oximeters to monitor blood oxygen saturation levels at high altitudes. It helps to detect altitude sickness at an early stage. In emergencies, we deploy a helicopter to transfer you to a medical treatment center (funded by insurance).

So, with Discovery World Trekking, you need not worry about altitude sickness. To plan your next trek in the Himalayas, you can call/Viber/WhatsApp at 9779840055491 or email [email protected]


Paul Gurung

Paul has an extensive experience in the tourism industry. Through his blogs, he shares his deep knowledge about the stunning trek regions in Nepal, inspiring trekkers worldwide to explore these regions and enrich their lives. In addition to geography, his writings delve into the human side of the trek regions, including culture, traditions, religions, and etiquette, offering a comprehensive and enriching perspective on the Himalayan trekking and expedition experience.