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  • Writer's pictureLMG Treks & Expeditions

How to avoid Altitude Sickness

Updated: Dec 3, 2022

Altitude sickness, technically known as Acute Mountain Sickness (AMS), is quite rightly a concern for anyone going to altitude. This said, there are a few basic rules to follow to give yourself the best possible chance of AMS not ruining your trip. So, what can you do to prevent it, and what happens if you get it?

At the high point of the Manaslu Circuit

As you ascend a mountain the amount of oxygen molecules you consume per breath decreases. It is once you get above approximately 2,500m the level of oxygen drops to a point where the body must make adaptions (acclimatise) in order to operate effectively. Rapid gains in altitude above this height (or to this height) can bring on symptoms of AMS, as well as much more severe illnesses such as HAPE (Fluid build up on the lungs) or HACE (fluid build up on the brain).

Symptoms of Altitude Sickness

The primary symptom of Altitude Sickness is a headache. Given the fact that you're away from home, sleeping in beds of varying comfort, maybe not getting much sleep at all, exercising for several hours a day in warm temperatures, getting a headache does not mean you have AMS.

AMS carries other symptoms, and should you have any of the below, coupled with a headache, then this is a strong indicator you're suffering with AMS:

  • dizziness

  • insomnia

  • lack of appetite, nausea, or vomiting

  • exhaustion or weakness

  • pins and needles

  • shortness of breath upon exertion

  • feeling sleepy

  • general malaise

  • swelling of the hands, feet, and face

How do I avoid Altitude Sickness?

'Altitude sickness doesn't discriminate' is a very apt term. Gender, sex, race or age have no influence on whether you're likely to get it or not. Some people will be more susceptible than others, but the likelihood is that if you have been to altitude before and adapted well (acclimatised) then I'd expect you to have similar success.

Whether you've been to altitude before or not, there are some basic rules to follow to help ensure your success.

- 'Bistare, Bistare' (Slowly, Slowly)

A phrase you'll hear in Nepal as we ascend. The aim is to not over exert yourself. At altitude the pulse and breathing rates will increase, and so keeping the pace slow and steady limits the output of the body during the acclimatisation phase.

Steady away on the trail

- Don't ascend too much in a single day.

Huge increases in height in a single push is too much for the body to handle and can bring on symptoms of AMS. Official guidance is no more than 305m a day if trekking over 3,000m. Of course progress must be made on expeditions and limiting to just 305m ascent a day could make an expedition very long! If more ascent than this is required then we follow the ethos of 'Climb High, Sleep Low'. This is where during the day we will reach a high point, during which it will boost our acclimatisation to that level, and then sleep lower, taking the strain off the body once more.

Our itineraries are designed to allow sufficient acclimatisation and rest periods.

- Stay Hydrated

As previously mentioned, you're hiking all day, usually in warm temperatures and so getting a headache could easily occur and cause unnecessary altitude sickness concerns. AMS is usually accompanied by fluid loss, so aiming to drink 3-5 litres a day whilst ascending is key. Furthermore, avoiding alcohol whilst ascending helps prevent dehydration.

- Eating Carbs

Fortunately eating a carb rich diet in countries such as Nepal isn't tricky

- Get as fit as you can

The fitter you are, the less exhausted you will be, which in turn can have an impact on bringing on the symptoms of AMS. So if you have a trip booked, start training now. If you need a hand, get in touch with us over at LMG Personal Training

So what happens if you show symptoms of Altitude Sickness?

If all of the above has been adhered to and you're showing symptoms then the indication is your body is not acclimatising. The first thing that must happen is you must stop ascending. Even better than this, is you must start to lose altitude until the symptoms disappear. If this happens to you, does this mean your trip is over? The answer - it depends. It depends on where you are and what the following itinerary. The thought of not reaching the top of a mountain or a main goal of the trip (Everest Base Camp for example) is no reason to hide symptoms you may be experiencing from the trekking team. It's great to reach the peak, but getting home alive is the real priority, and put quite simply, ignoring symptoms of AMS can lead to death.

Our team of guides and trek managers are trained in spotting symptoms of altitude sickness, however being transparent about how you feel helps the team to build a picture of what the issue may be.

Should I take Diamox?

Diamox, also known as Acetazolamide, is a drug that is used to treat altitude sickness, amongst a whole host of other illnesses or conditions. Diamox is not a magic pill to eliminate the chance of altitude sickness and it does have side effects such as tingling fingers and lips or alteration of taste. We recommend you do obtain Diamox for your expedition to altitude (can be bought online or go to your GP) and many start taking it from day 1 of the trip. Allergic reactions to Diamox are possible so taking a tablet before heading on expedition as a test is also wise.

You can opt to not take Diamox if you wish. Many people don't take the drug have have successful expeditions to altitude with no altitude sickness, whereas others are prescribed a dosage every day irrespective of how they feel.

Here are some scenarios whereby Diamox can be useful:

  • For early mild acute mountain sickness (headache, fatigue, dizziness, loss of appetite) the Diamox (acetazolamide) dose is 250mg (one tablet) twice daily. Taking Diamox (acetazolamide) will help with these symptoms. The important thing is not to ascend until the symptoms resolve.

  • Sleep disturbance of altitude is treated with 125mg (half a tablet) Diamox (acetazolamide) twice daily

  • in situations where rapid forced ascent cannot be avoided the dose of Diamox (acetazolamide) is 125mg (half a tablet) twice daily. Ascent of more than 500 metres (1,500 feet) a day above 3,000 metres (10,000 feet) is dangerous with or without Diamox (acetazolamide).

It is very important you seek professional medical advice when obtaining your Diamox, and understanding the array of side effects is also wise.

If you are on one of our trips we will make you aware of the positives and negatives, but ultimately your decision whether to use Diamox is your decision based on your prescription and research.

What if you get really sick?

Then it is a case of evacuating you to a much lower altitude as swiftly as possible. An initial response may be to pop you into a Gamow bag which effectively creates a sealed atmosphere of 3000-5000ft lower than the one you're at. After some time in the Gamow bag you will either be able to descend on your own two feet, or be loaded into a helicopter. If it gets to this point then unfortunately your trek is over.

The above text is a basic outline of altitude sickness and some of the main ways in which getting ill at altitude can be avoided. As a company, we ensure our itineraries allow sufficient opportunity to acclimatise. Our guides will keep the pace slow and steady, and will use their vast experience to identify any illness, and take appropriate action as required. We always try and discourage people worrying too much about altitude sickness as it can become psychologically draining, so just follow the simple steps above and you'll give yourself the best possible chance. If you still get sick, then you've done all you can and there will be some solace on that whatever that means for your trip.

Taking some time on the trail. Pumori stands beyond.

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