The essentials:
- Acute Mountain Sickness (AMS) appears from 2500 meters altitude.
- Don't go too fast, too high.
- Don't stay too high, for too long.
- Any discomfort or symptom at altitude = lack of acclimatization = STOP or descent.
For further :
Excursions and hikes at altitude must be subject to a specialist medical advice before leaving.
Le Acute Mountain Sickness Altitude sickness (AMS) is linked to a decrease in atmospheric oxygen pressure and, consequently, to a lack of oxygen in the body. It occurs when acclimatization is inadequate, which is why several days are needed to adapt to these particular environmental conditions.
AMS manifests as shortness of breath, headaches, insomnia, loss of appetite, nausea and vomiting, and can lead to serious complications (pulmonary and cerebral edema) that are life-threatening. It occurs more frequently the faster the ascent.
The rules for preventing AMS are as follows:
- Avoid any intense effort at the beginning of your stay (and if possible, take a few days to acclimatize);
- Don't climb too fast… (take a 5-minute break every 30 minutes of walking)
- …too high! (no more than 500 meters of elevation gain per day)
- Stay hydrated and avoid alcohol consumption;
- Don't stay too high, for too long;
- Analyze your symptoms and react:
Any discomfort or symptom at altitude is a sign of poor acclimatization. (often between 4 and 8 hours after arrival at altitude):
- Stage 1: Shortness of breath on exertion, mild headaches relieved by Paracetamol → Rest for a few hours before resuming the climb.
- Stage 2: Shortness of breath on exertion, nausea/vomiting, headache not relieved by Paracetamol → STOP: stop for 24 to 48 hours at the landing where you are, then resume the ascent if the symptoms disappear.
- Stage 3: Shortness of breath at rest, decreased urine output, balance problems/dizziness → STOP: Descent by the medical team in a hyperbaric chamber.
In children, the risk of acute mountain sickness (AMS) is similar to that in adults. Before the age of 3, the signs are more subtle (irritability, anorexia, apathy, insomnia), and up to 12 months of age, the risk of sudden infant death syndrome (SIDS) is high at altitudes above 1600 meters. High altitudes above 2000-2500 meters are not recommended for infants.
To avoid the occurrence of a gas embolism, a 24-hour interval must be observed between air travel and a stay at high altitude.
Source: Guide to Health Recommendations from the High Council for Public Health for Travellers
