Physical Fitness

I like this next bit being a bit of a lazy fellow.  It does not matter how fit you are - you can still get AMS.  Even experienced Himalayan mountaineers who have climbed Everest in the past can return to Nepal and get AMS.  It happens.  Believe it.

It should go without saying that if you have heart disease, difficulty breathing at sea level or pregnant then don't plan on going to high altitude.  Relax - you can still go trekking and there are plenty of stunning lower treks and things to do in Nepal.

Any other chronic conditions that you may have will require you to have a discussion with your doctor at home.

Don't expect everyone in your party to acclimatise at the same rate.  As previously stated, people vary and you must be prepared to build in rest days or split the group. Children are more susceptible to AMS and infants can't articulate what their symptoms are...so keep 'em low down.

Altitude

You are very likely to be going higher in the Himalayas than you have ever been under your own power.  Everest Base Camp itself is 1000m higher than the highest mountain in Europe.  Being there is a great experience but it takes time for your body to adjust to this altitude.  The key word is 'time'.  Take your time.  Enjoy and savour the views and the culture but DON'T HURRY.  The mountains have been there for a long time - they aren't going anywhere just yet.

The process of getting used to the increasing height is called 'acclimatisation' and you must acclimatise gradually.  There are no quick fixes or magic pills that can replace time. (No - not Diamox if you've heard of that.  More on that further down but read this stuff first).

If you are into the sums and want some kind of calculation then the recommendation is that once you are above 3000m (ridiculously easy in Nepal) then you ascend no more than 300m per day on average.  This is not a prescription.   People vary. But if you are going to vary then vary it 'down' to less activity and height gain, not more.

With that in mind also consider that carrying a heavy pack which leads to extra exertion can predispose people to AMS.  Even if you are a world class athlete and fit as a fiddle this applies.  In fact it is more of a risk as you will be tempted to bite off more than you can chew and sideline any considerations you might have had about acclimatisation.  There is a lot of evidence to support this.  Slow down.  Relax.

Recognising AMS

I've mentioned 3000m as a figure but AMS can develop at any altitude above 2000m.  The early symptoms are headache, extreme tiredness and loss of appetite.  You may feel breathless at rest.  Mild AMS sufferers may become withdrawn from the group. Even if you feel fine, keep an eye on your companions.  One thing that I have learned on my treks in Nepal is that sufferers will often try to explain away their feelings of 'not wellness' with any old reason (beer the night before, cold symptoms, jet-lag) rather than believe that the altitude is making itself felt.

At this point AMS is not life-threatening.  Nature is telling you to STOP and rest.  You should be okay. Take a rest day.  Hell, take 2 days.  Usually your body will have caught up with the altitude during this period and it will be safe to continue up.

If, however the symptoms have not gone away and you are resting as above then you will have to go down.  Usually a very small amount of height lost will clear the symptoms.  Maybe the last place where you felt okay.  

Failure to descend will result in a worsening of symptoms which include increasing tiredness, severe headaches, vomiting and a loss of coordination.  If this happens then you can be sure (if you are in a position to self diagnose it as opposed to insisting that it was a dodgy dal baat) that High Altitude Cerebral Oedema is causing the problem.  HACE can lead to unconsciousness and death within 12 hours if these symptoms are ignored.

If this is happening to one of your party then the sufferer must descend.  MUST DESCEND!.  Also do not have the person going down alone.  A fit person must accompany them.  After about 500m of descent the sufferer will usually show obvious (sometimes miraculous) signs of improvement.  You can both re-ascend after a suitable time at lower altitude.  Many people do with no ill effects.

Do not mess about waiting for a helicopter.  It won't happen in time.  No negotiation on that.  Descend immediately even if it is the middle of the night.  In fact it's very likely to be the middle of the night. AMS symptoms love the night-time when you are resting.

Do not waste time administering oxygen and then waiting for an improvement.  Anyway - how likely is it that you will have oxygen?  AMS is a pressure problem.  Oxygen might just give relief if, as I say, you have it.

Other Bits and Pieces about AMS

Don't use sleeping pills or sedatives at altitude.  The same goes for alcohol.  Yes, I know that you can buy beer at the highest lodge but it is not compulsory to drink it. Really.

Drink lots of water to prevent AMS.  How much is 'lots'?  About 4 litres of boiled or iodined water per day to avoid dehydration helps in the acclimatisation process.  Go to the toilet a lot. Remember ' a happy mountaineer always pisses clear'.  It's true.  If your urine is dark then you are dehydrated.  Have some more to drink.

I haven't forgotten about HACE's near relative HAPE (High Altitude Pulmonary Oedema).  Dry hacking coughs and hawking up dark coloured phlegm can be an indication that the altitude is affecting the breathing process, squeezing out fluid from cells into places that fluid shouldn't be - think 'drowning' and that'd be about right.  I say 'can be an indication' when really you should be so savvy as to treat anything as possible AMS symptoms.  Symptoms can appear individually or with a combination of the others.  Everybody is different.  Be cautious. Be safe. A cough might be the result of a smokey teahouse but why take the risk?  In a hurry?

Acetazolamide (Diamox)

The jury is still out on the taking of diamox but it is effective.  For a start it makes you piss as it is a diuretic.  It assists breathing.  In short it assists the process of acclimatisation but it is not a substitution for acclimatisation.  I tried it once when I was a little unsure about my own acclimatisation routine.  I only had half a tablet and it made my hands and toes tingle - not an unpleasant sensation and a recognised side effect.  The funniest (not) part was getting up most of the night to go to the toilet.  Such fun.

Follow the link below for the High Altitude Medicine Guide to get an expert view on this drug.

Don't go to Nepal without looking at this site: www.high-altitude-medicine.com

Also - don't forget my main source for this page, the Himalayan Rescue Association.  You can visit them at their office in Tridevi Marg in Thamel, near to where you will have to pick up your National Park permit.  Oh - and the HRA is a charity so any donations are not just welcome, they are vital.  Read the Trekkers Log Book that is kept there and see what the  latest news on the trails is.  Heck - buy the T-shirt  (Rs500).

Click here for the HRA website and enjoy your trek.  Know your enemy - AMS.