Altitude and safety
Altitude sickness in Nepal: acclimatisation and safety
Above 3,000 m, your body needs time. These simple rules prevent most problems; they don't replace a doctor's advice.
Acclimatisation rules
- Above 3,000 m, don't sleep more than 300 to 500 m higher than the previous night.
- A rest day every 3 to 4 days, or every 600 to 1,000 m of elevation gain (Namche and Dingboche for Everest, Manang for the Annapurna Circuit, Samagaon for the Manaslu).
- Climb high, sleep low: rest-day side trips (Ice Lake, Nangkartshang…) help you acclimatise.
- Drink regularly and avoid alcohol for your first days at altitude.
On each trek page, the “Vs prev.” column of the itinerary shows the altitude difference from the previous night: look out for days that gain more than 500 m above 3,000 m.
Recognising altitude sickness
| Signs | What it may be | What to do |
|---|---|---|
| Headache, nausea, fatigue, poor sleep | Acute mountain sickness (AMS) | Don't go any higher; rest, water. If it doesn't pass or gets worse: descend. |
| Breathlessness at rest, cough, extreme weakness | High-altitude pulmonary oedema (HAPE) | Descend immediately, even at night, and get help. |
| Confusion, loss of balance, unusual behaviour | High-altitude cerebral oedema (HACE) | Descend immediately, accompanied; life-threatening emergency. |
The golden rule: never go up with symptoms. If in doubt, go down: a few hundred metres is often enough to feel better.
Rescue and prevention
- Himalayan Rescue Association: aid posts and altitude talks in Manang (Annapurna Circuit) and Pheriche (Everest) during the season.
- Acetazolamide (Diamox): talk to your doctor before you leave; it doesn't exempt you from following the acclimatisation rules.
- Insurance: check that it covers trekking at the trek's altitude (at least 5,500 to 6,000 m for Everest or the Thorong La) and helicopter evacuation.
What about the visa? A two-week trek plus a few days in Kathmandu and Pokhara quickly adds up to more than 15 days: get the 30-day visa. The calculator on our sister site Visa Nepal shows the cheapest length.
Which visa length?Comments
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