Home > High Altitude Sickness

What is high altitude sickness?
High altitude sickness is a potentially serious medical condition that can develop when you are physically active at high altitudes without having become acclimatized to the lower pressures experienced there.
Of course, altitude and air pressure tolerance varies widely from person to person. People who are more fit tend to have less trouble with AMS. However, even very fit people are vulnerable to AMS if they trek too high in too short a time, or without acclimatizing properly.
AMS hits some people at altitudes as low as 2,400 metres (8,000 feet), but serious symptoms are quite rare below 3,700 metres (12,000 feet). It is the lack of oxygen, coupled with physical exertion that most often triggers AMS.
At 5000 metres the air pressure (and the amount of oxygen available to you with each breath) is only 55% of that at sea level. At 6000 metres it is less than half. This has a major impact on the body’s physiology. AMS is not always a gradual worsening of the kinds of mild altitude related symptoms most people experience, including headache and shortness of breath. It can have a rapid, severe onset and can completely disable a trekker in minutes.

What are the symptoms of high altitude sickness?
If at any time you are above 2,400 metres and experience a headache coupled with one or more of the following symptoms, you may be experiencing high altitude sickness, and must report this to your guide for assessment.

  • Vomiting, nausea or loss of appetite
  • Weakness or fatigue
  • Feeling light-headed or dizzy
  • Difficulty sleeping
  • Numbness, pins and needles
  • Shortness of breath
  • Rapid pulse (especially if persistent)
  • Sleepiness or drowsiness
  • Overall malaise
  • Swelling or oedema of face or extremities
  • Disorientation or confusion
  • Unusual behaviour
  • Fatigue
  • Difficulty speaking or walking
  • Nausea or vomiting
  • Hallucination or vision problems

What causes high-altitude sickness?
The higher you climb above sea level, the less oxygen there is in the air. The oxygen level becomes very low at altitudes above 8,000 feet. This causes problems for people who normally live at lower altitudes because their bodies aren’t used to working on so little oxygen. If you stay at a high altitude for a long time, your body gets used to the low oxygen level, and you don’t get sick from it.

How can I prevent high-altitude sickness?
‘Walk High, Sleep Low’
We make every effort to give you the opportunity to do a short walk at a higher altitude every day, rest there for approximately 30 minutes, then descend again to sleep.
Go slowly!
You need to maintain a breathing rate low enough that you could easily maintain a conversation. If you find you are breathing hard, slow down. Overworking your heart and lungs puts you at much higher risk of AMS.
Drink more than you feel you need to
Proper hydration not only makes AMS less likely, it makes you less vulnerable to a host of other problems as well. To protect yourself, you need to drink at least 3 litres of water each day, especially if you don’t feel thirsty. If your urine is yellow (or worse, orange) you are not drinking nearly enough.
Dehydration can be mistaken for HACE, and cause you to be taken back down the mountain, so drink up!

What should I do if I get high-altitude illness?
The best treatment for any of the 3 high-altitude illnesses is to go down to a lower altitude right away. But if you only have mild symptoms, you may be able to stay at that altitude and let your body adjust. If you do this, don’t exercise at all–just rest until you feel better.
If you have severe symptoms, go down 1,500 to 2,000 feet right away to see if your symptoms get better. Keep going down until your symptoms go away completely.
Medicines that may be used to prevent or treat the symptoms of severe high-altitude illness include acetazolamide (one brand name: Diamox) and nifedipine (one brand name: Procardia).
Don’t ignore signs of high-altitude illness. People can die of this if they don’t recognize the signs or if they don’t believe their illness is caused by the high altitude. When you have signs of high-altitude illness.  Don’t go higher until you feel better and your symptoms have gone away completely.

Is it safe to go to a high altitude if I have a chronic illness like heart disease or lung disease?
It depends on the type and severity of chronic illness you have. Most people who have a chronic illness, such as heart or lung disease, can safely spend time at a high altitude if their disease is under control. People who have coronary artery disease, mild emphysema or high blood pressure aren’t at greater risk of high-altitude illness than people who don’t have these diseases. They also don’t risk making their disease worse by traveling to a high altitude. In addition, being overweight does not increase the risk of getting high-altitude illness.
Some diseases make going to a high altitude very dangerous. People who have sickle cell anemia shouldn’t go to a high altitude. A high altitude is also dangerous for people who have severe lung disease, such as chronic obstructive pulmonary disease (COPD) or severe emphysema.  Also  for people who have severe heart disease. If you have a chronic disease, ask your doctor if it’s safe for you to travel to a high altitude.

Is going to a high altitude dangerous during pregnancy?
There isn’t much information about the risk of high-altitude illness during pregnancy.  So it’s hard to say if going to a high altitude is safe for pregnant women. Some experts recommend that pregnant women not travel to an altitude above 8,000 feet. If you’re pregnant, ask your doctor for advice before you travel to a high altitude.

What about children and high altitudes?
It’s usually safe for children to go to high altitudes, but they’re more likely to get high-altitude illness.  Because their bodies have a hard time adjusting to the low oxygen level. A child may not be able to recognize the symptoms of high-altitude illness.  So parents and other adults must carefully watch for any signs of high-altitude illness in children.