The Three Passes trek keeps you high for a long time. After Namche you sleep above 4,000 m for most of two weeks, and you cross three passes above 5,300 m. That makes altitude the main health risk on the route, and it is the reason a slow schedule matters more than strong legs. This is general guidance only and does not replace medical advice or your guide's decisions.
How acclimatisation works on this route
The body adapts best to gradual change. A common guideline is to add only about 300 to 500 m of sleeping height per day once above 3,000 m, and to take a rest day roughly every 1,000 m of gain. The Three Passes route fits this pattern if the rest days are kept at Namche, Gokyo and near Dingboche or Lobuche. If an itinerary drops these days, the risk rises.
Early signs to watch for
- Headache that does not go away with rest, water and simple pain relief.
- Nausea, loss of appetite or unusual tiredness.
- Dizziness or poor sleep beyond the usual restlessness at altitude.
- Shortness of breath at rest.
Signs that mean descend now
Confusion, loss of coordination, difficulty walking in a straight line, a persistent wet cough, breathlessness at rest or severe headache are danger signs. Do not wait until morning. Tell your guide at once, descend and seek medical help. Never go higher while symptoms are getting worse.
Habits that help
- Walk slowly, even when you feel strong.
- Drink water regularly through the day, as dry air increases fluid loss.
- Eat even when appetite is low.
- Avoid alcohol and sleeping pills at height.
- Tell your guide how you feel every evening.
Pass days and altitude
On a pass day you climb steadily, spend a short time at the top and then drop. The descent often makes people feel better, but cold, tiredness and dehydration can still cause problems. Start early, keep eating and carry enough water. If you feel unwell on the way up, tell your guide so that the group can turn back before the point of no return.
Medicines and insurance
Some trekkers ask a doctor about preventive medicines before the trip. Decide this in advance with a medical professional, not on the trail. Make sure your travel insurance covers trekking to 5,500 m and helicopter evacuation, and keep the policy number with you.
