The Symptoms of Altitude Sickness
Altitude sickness is the most common health problem for visitors to Tibet. Knowing the symptoms before you go helps you react early, which matters most if you plan to trek or visit places above 4,000 m.
Above 3,000 m, a good rule is to raise your sleeping altitude by no more than 300 to 500 m a day. Going up faster than your body can adjust is what causes Acute Mountain Sickness (AMS).
Normal Acclimatization Symptoms
These are normal and not a reason to worry:
- poor sleep for the first few nights
- needing more sleep than usual
- less appetite
- vivid dreams
- breathing that changes rhythm while you sleep
- getting out of breath quickly when you walk uphill
- a runny nose
- needing to pass water more often (a good sign that your body is adjusting)
Mild AMS Symptoms
If you have a headache plus one or more of these, you have mild AMS. Rest, drink water and do not go higher until you feel better:
- nausea or dizziness
- weakness and tiredness
- loss of appetite
- trouble sleeping
- a dry cough
- feeling breathless
Dangerous Altitude Sickness
There are two life-threatening forms of altitude sickness. Both usually affect people who go up too fast or who keep going up with symptoms.
HACE — High Altitude Cerebral Edema
Fluid builds up around the brain. Warning signs are a severe headache that painkillers do not help, vomiting, confusion, strange behaviour and unsteady walking (the person cannot walk heel-to-toe in a straight line). Without treatment it can lead to coma and death within a day.
What to do: go down at once, give oxygen, and get medical help. A doctor may give dexamethasone.
HAPE — High Altitude Pulmonary Edema
Fluid builds up in the lungs. Warning signs are breathlessness even when resting, a wet cough, a tight chest, blue lips and very fast tiredness. It is the most common cause of death from altitude.
What to do: go down at once, give oxygen, keep the person warm and sitting up, and get medical help. A doctor may give nifedipine.
Emergency rule: if you think someone has HACE or HAPE, don’t wait until morning. Go down and get medical help straight away. Tell your guide at the first sign of serious symptoms. On our tours the guide carries oxygen and knows the nearest hospital on every route.
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