High Altitude Sickness and Prevention

High altitude sickness, also known as acute mountain sickness (AMS), is a common condition that affects individuals who ascend to high altitudes too quickly. It typically occurs at altitudes above 2,500 meters (8,200 feet) and can range from mild symptoms to life-threatening conditions. In Nepal, home to some of the world's highest peaks, including Mount Everest, AMS is a significant concern for trekkers and climbers.  Here's an overview of high-altitude sickness and its prevention while trekking in Nepal.

Causes of Altitude Sickness in Nepal

  • Reduced oxygen levels at high altitudes
  • Rapid ascent without proper acclimatization
  • Physical action at high altitudes

Basic Symptoms of high-altitude sickness while trekking in Nepal (Mild AMS)

  • Headache
  • Nausea and vomiting
  • Dizziness
  • Fatigue
  • Shortness of breath
  • Difficulty sleeping
  • Loss of appetite
  • Severe Symptoms (HACE & HAPE)
  • Severe headache not relieved by medication
  • Increased vomiting
  • Loss of coordination (ataxia)
  • Confusion
  • Shortness of breath at rest
  • Chest tightness

Prevention tips for altitude sickness while trekking in Nepal

  • Gradual Ascent
  • Climb and walk slowly to allow the body to acclimatize
  • Follow the "climb high, sleep low" rule: climb to a higher altitude during the day, then descend to sleep at a lower altitude if possible.
  • Aim to ascend no more than 300-500 meters (1,000-1,500 feet) per day once above 3,000 meters (10,000 feet)

Acclimatization Days

  • Take rest days to allow your body to adapt to the high-elevation
  • Take rest days for acclimatization every 2-3 days or after every 1,000 meters (3,300 feet) of ascent

Stay Hydrated

  • Drink plenty of fluids (water, herbal tea) to stay hydrated, as dehydration can exacerbate AMS symptoms
  • Avoid alcohol as much as you can.


  • Consider using Diamox (acetazolamide) as a preventive measure, but consult with a doctor beforehand
  • Avoid sleeping pills and other depressants.

Proper Nutrition or Diet

  • Eat a high-carbohydrate diet, which provides more energy and aids acclimatization.
  • Do not eat non-veg items and heavy meals.
  • Maintain a high-carbohydrate diet to provide sufficient energy.

Avoid Overexertion

  • Limit tireless activities, especially in the first few days at high altitudes.
  • Listen to your body and rest if you feel tired or unwell.

Emergency Measures

  • Immediate descent: The most effective treatment for AMS, HACE, and HAPE is to go lower altitude ASAP.
  • Supplemental Oxygen: Using supplemental oxygen can help alleviate symptoms and stabilize the patient until descent is possible.
  • Portable Hyperbaric Chambers: These are inflatable bags that simulate lower altitudes by increasing air pressure and oxygen levels, useful in remote areas.
  • Evacuation: In case of severe AMS, HACE, or HAPE, arrange for helicopter evacuation if descent on foot is not feasible.


High altitude sickness is a serious concern for trekkers and climbers in Nepal, but proper preparation and preventive measures can reduce the risk. Gradual ascent, adequate hydration, appropriate medication, and recognizing early symptoms are vital in ensuring a safe and enjoyable experience in the majestic high altitudes of Nepal. Always prioritize your health and safety, listen to your body, and be prepared to adjust your plans if necessary.