If you only remember one thing from this article, make it this: Mountain Sickness can kill. But Mountain Sickness isn’t just one illness, it’s a long scale of symptoms from feeling a bit funny to unconsciousness and death.
However the good news is that with a little preparation you can remain at the funnier end of the scale, and not suffer anything worse than a mild headache.
Before you go
Preparing for altitude shouldn’t happen on the plane - give yourself a long lead-in and think clearly about your objectives. And don’t be cocky now, stats show that the younger and fitter you are, the more susceptible you are to getting Acute Mountain Sickness (AMS), probably because younger people find it harder to slow down and take it easy. Walking at altitude is all about taking your time - a crime in this modern age. But this doesn’t mean you need to start blobbing out before your trip, since a good standard of cardiovascular fitness is the basis of all good health. So before you go away aim for 30 minutes hard exercise three times a week to maintain cardio fitness. And if chips and ale are more important to you than the latest trainers, then you’ll need to do a bit more.
As you acclimatise, your body needs more water to adjust its fluid levels, you also exhale more moisture as you breath dry mountain air. Add this to the fact that you’ll be working harder due to the reduced levels of oxygen in the atmosphere and you start to see a real need. As a guide you should be drinking about four litres of fluid a day, the majority of this being water. Sadly the average adult in the UK drinks about two litres a day, the majority of this being tea, coffee and beer. The other way to see if you are drinking enough is to take note of the colour of your urine. If it’s clear and copious that’s good.
Other areas of preparation are rather more obvious. Think about your route, accommodation and escape plans to minimise your load. Food needs careful consideration. The average adult requires 2000-2500 calories a day to work effectively, but at altitude the body doesn’t deal too well with fats and proteins. Your normal diet will have to change, a diet rich in carbohydrates is the way to go - the anti-Atkins if you will. As you ascend you’ll also find that water boils at a lower temperature. At first this isn’t a big deal, but food will take longer and more fuel to cook. And if you’re planning to purify your water by boiling then that’s more fuel gone.
Preparation will give you a better chance of enjoying walking at altitude, but the real key is proper acclimatisation. It’s normal above 3000m for the reduced levels of oxygen to cause slight headaches, lethargy, sleeplessness and a lack of appetite. But after being at a similar altitude for a day or so the body adjusts to this new altitude and goes back to normal - it’s acclimatised. Different people adjust at different rates so don’t worry if you don’t acclimatise in a day. But if any of the symptoms get worse you shouldn’t go any higher - they’ll only increase. Wait two or three days to see improvement, and remember, in all cases of altitude related illness going down 500-1000m can improve things or even cure you.
Yet if you decide that you’re superhuman and rush the acclimatisation phase, then you have some great symptoms waiting for you. At altitude the fine tissues in your lungs and head that normally act as barriers start to get leaky. If you acclimatise slowly then this fluid, called oedema (edema for Americans) is managed by your body and carted off. If not, then it builds up. If the oedema builds up in the head, it’s called cerebral oedema, if it’s in the lungs its called pulmonary oedema. High Altitude Cerebral Oedema (HACE) and High Altitude Pulmonary Oedema (HAPE), are the killing end of AMS. The symptoms of HACE unsurprisingly are massive headaches, lack of balance and dizziness as the pressure builds up in your head. The symptoms of HAPE are an increasingly bad cough, breathlessness at rest and blood stained mucus as your lungs fill with fluids.
It’s all about preparation. So start reading and clicking your mouse now, but don’t forget to get active. Have a great time, walking at altitude can be safe and fun. But don’t forget to take it slowly, and if in any doubt remember there is a simple cure - go down, go down now, and go down again!
Medex have published a useful booklet on these issues that can be freely downloaded.
MIC Ed Chard is a self-employed expedition leader. He has led expeditions to altitude for the last ten years mostly in the Greater Ranges. When at home Ed is available for rock climbing, winter climbing and technical advice. For more info visit edchard.co.uk
This issue the medical expert is Dr David Hillebrandt. Dave has over 35 years hill experience, is one of the BMC Honorary Medical Advisors, and Vice President of the UIAA Medical Committee. Over the years he has experienced cracking AMS headaches on Mt Kenya and in the Himalaya, so now tends to explore the mountains of Patagonia which start at sea level and only involve sea sickness on the approach.
Q. What’s Diamox?
A. Diamox (Acetazolamide) is a mild diuretic drug primarily used in the UK for the treatment of Glaucoma. Good quality research has shown that it is effective in preventing AMS by increasing the amount of oxygen carried in the arterial blood via a complex series of actions altering the acidity of the blood and driving the body’s natural breathing mechanism. It can be very useful to help people who have to go too high too quickly (e.g. rescue personnel). It is also used by some climbers and trekkers to minimise AMS but one has to consider the ethics of using drugs in sport, or in the case of some commercial companies, to increase their profits. It’s no substitute for proper gradual acclimatisation, but if you must take it, international opinion seems to be that 125mg twice a day is the optimum balance between effectiveness and potential side effects.
Q. Do acclimatisation chambers work?
A. There is no evidence to show they help mountaineers. It’s much better to spend your money on a longer trip to acclimatise sensibly and enjoy the culture and geography, which is impossible sitting in a miserable little chamber.
Q. How do I know my tour operator will use a recommended rate of ascent?
A. Don’t be afraid to ask pertinent questions. You’ll be spending a lot of hard-earned cash so expect answers. Look for a tour operator with a proven track record, and all reputable operators will be able to produce a chart of the proposed ascent profile. A company with a good reputation will not think it odd for you to ask their rate of success with clients, so ask about the experience and mountain medicine training of their leaders and local agents and guides. Ask who would accompany you (or one of your porters) down if either of you became ill? How much experience would this person have? Do they carry and know how to use appropriate drugs in their medical kit to buy time for descent, the only real treatment. Compare companies - as always, you get what you pay for.
Q. What’s the difference between a headache and the start of something more serious?
A. There is no difference. The mild headache of AMS can progress to the cracking headache of HACE over a few hours, and then to death. Anybody with a headache associated with ascent should monitor themselves, but also have a companion monitor them, even if it means waking hourly during a cold night in a tent. If an increasing headache is associated with loss of coordination you have major problems and must descend immediately.
Q. At what height would I need to use oxygen?
A. Not until above about 8,850m if you have taken time to acclimatise and are one of those lucky, possibly partly genetically predetermined, people who acclimatise well. Having said that some people choose to use it at lower altitudes. It’s a balance between cost, weight, supply problems, flow rates, altitude, continuous use, sleeping use, reliability of the system used and personal feelings. The only way to truly find out is to build up your experience over many trips over many years and then make a personal decision in discussion with the companions on your trip.
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