This guide is about altitude sickness on Nepal treks, written from what we see on the trail every season.
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Altitude sickness is the main thing to plan for on a high Nepal trek. It has little to do with how fit you are, and a lot to do with how slowly you climb. The good news is that the habits that help are simple, and most of them are free.
This guide covers the basics for any route in Nepal. If you are heading to Everest specifically, we also have a closer look at altitude sickness on the Everest Base Camp Trek.
What altitude sickness feels like
Mild symptoms often start above about 2,500 to 3,000 metres. Common ones are a headache, feeling sick, dizziness, poor sleep, and less appetite than usual. Feeling tired is normal on a trek. A headache that keeps getting worse is a different thing, so pay attention to it.
More serious signs include confusion, trouble walking in a straight line, breathlessness even when resting, and a cough that will not settle. These need action straight away, not a wait-and-see approach.
Go up slowly
The biggest factor is how quickly you gain height. Above about 3,000 metres, a widely used rule of thumb is to raise your sleeping height by roughly 300 to 500 metres a day, and to take a rest day every so often. Walking slowly and steadily is better than racing to the next lodge.
Do not be tempted to shorten a route to save time. A trek with more days is usually kinder to your body than a rushed one.
Acclimatisation days are not wasted days
An acclimatisation day gives your body time to adjust. The usual approach is to walk higher during the day, then come back down to sleep. Here are the ones in our own itineraries, which you can check on each trip page:
- Everest Base Camp Trek: one day in Namche Bazaar and one day in Dingboche.
- Annapurna Circuit Trek: one day in Manang before the climb towards Thorong La.
- Manaslu Circuit Trek: one day in Samagaon before the Larkya La.
We only list the days that appear in those itineraries. If you are looking at a different high route, ask us how it is paced before you book.
Drink water and look after the basics
Drink regularly through the day, and keep an eye on the colour of your urine as a simple check. Eat even when your appetite is low. Go easy on alcohol at altitude, and rest properly at night. Wear layers so you stay warm and avoid wasting energy.
None of this is a guarantee. Altitude affects different people differently, and nobody can promise you will not feel it.
Tell your guide early
This is the most useful habit of all. If you have a headache, feel dizzy, or just feel off, say so on the same day. Do not wait until the evening, and do not hide it to keep the group moving. Guides would much rather hear about small symptoms early than deal with big ones later.
Our guides check in with every traveller each day. On our trips the guide also carries a first aid kit with an oximeter. It is a helpful tool, but it does not replace you telling us how you feel.
When to stop, and when to descend
Keep this simple rule in mind:
- Mild symptoms: stop going higher, rest, drink water, and tell your guide.
- Symptoms that are not improving: do not climb further. Stay at the same height or go lower.
- Symptoms that get worse: descend.
- Severe symptoms such as confusion, trouble walking, or breathlessness at rest: go down urgently and get medical help.
Never keep climbing with worsening symptoms, and never send someone down alone if they are unwell. Going down is the single most reliable treatment there is.
Sort out insurance before you fly
If something goes wrong at altitude, you may need an urgent descent or a helicopter. Make sure your policy covers trekking to the height you plan to reach, including emergency evacuation. Our guide to travel insurance for trekking in Nepal explains what to check, and our travel insurance page has more detail.
A note before you go
This article is general information, not medical advice. Please talk to your own doctor before a high trek, especially if you have a health condition or are thinking about medication. We do not give advice on medicines.
Not sure which route suits you? Get in touch and we will happily talk it through.
Altitude sickness on Nepal treks: next steps
Use this altitude sickness on Nepal treks to shortlist your dates, then message us. We will check the altitude sickness on Nepal treks details against the season, the permit rules and your group before you commit to anything.
Questions about altitude sickness on Nepal treks that this page did not answer? Ask us and we will add the answer here.
A good altitude sickness on Nepal treks should leave you able to plan, and ours is built for that. Read the altitude sickness on Nepal treks once through, check the key details, then compare it with the trip page.
Our team is a member of TAAN, Nepal’s trekking agents association. If this altitude sickness on Nepal treks raised a question, ask us. A short recap of the altitude sickness on Nepal treks: check the season, check the permits, and plan the days before the price.