The most important aspect of staying healthy in the Himalaya is avoiding altitude sickness, which has been dealt with here.
The next five most important health issues you will face are dehydration, body temperature issues, sunburn, proper diet, and avoiding maladies like malaria and diarrhoea. Each is detailed below.
Dehydration can be a very serious issue when trekking at high altitudes. You must drink plenty of fluids (at least 3 litres a day, preferably more) each day or you risk serious health consequences and an early end to your trek.
The higher you climb, the harder your lungs have to work to get the same amount of oxygen. You will be breathing faster and more deeply, and therefore losing substantially more water through your lungs with every breath. This is in addition to the water lost through perspiration and increased activity.
There are two quick tests you can do yourself to determine if you might be dehydrated: the pinch test and urine colour. For the pinch test, pinch the soft skin on the back of your hand. It will remain white for a moment. If it returns to normal quickly, you are probably not dehydrated. If it stays pale for a few seconds you probably are dehydrated, and you need to increase your fluid intake immediately. For the urine test, if your urine is clear or a light straw colour, you are probably not dehydrated. If it is yellow or even orange, that means you probably are becoming dehydrated. It is concentrated because your kidneys are trying to conserve water. You need to drink more water before you notice any more serious symptoms.
The easiest way to stay hydrated is to drink more water. 3 litres a day is really the absolute minimum you should drink while trekking at altitude, whether you feel thirsty or not. Many people spoil their entire trek every year through ignoring their hydration, and not drinking enough. Don’t let it happen to you!
While hydration is important throughout your trek, it is never more important than during a summit ascent or when crossing a high pass. You will be under mental and physical stress, and it will be difficult to remember to keep drinking.
The best way to ensure dehydration does not become a problem on a summit ascent is to drink a full litre of water, tea or other fluids before you start the day’s climb. You will be given two litres of water to carry during the climb. Make sure it doesn’t freeze! Exposed bottles or drinking tubes freeze very quickly over 5000 metres. Keep your water bottles insulated in your daypack (by wrapping them in fleece, or stuffing them in thick socks). Pack them upside down, as water freezes from the top, and that way even a partially frozen bottle can still be used.
If you are climbing a peak above 6000m, we don’t recommend a platypus for a summit attempt but if you do use one make sure to keep the entire tube inside your jacket, as it can freeze and become blocked very easily. We strongly recommend keeping a back-up one litre wide mouth Nalgene bottle as well.
Lastly, we recommend in the strongest possible terms that you drink at least another litre of fluids once you get back to base camp. You will be exhausted, and won’t feel how thirsty you are until it is too late.
Regulating your temperature
Mountains have their own weather systems, and you can expect widely fluctuating temperatures from day to day as well as big shifts between day and night. Monday could be sunny and warm, followed by rain or even snow on Tuesday. The best way to adapt is to wear layered clothing, so you can always wear just enough to stay warm and dry without overheating.
If you will be making a summit attempt on your trek, you will absolutely need the best quality gear, especially warm, breathable and waterproof clothing. You can expect wickedly cold temperatures above 5000 metres, as well as high winds and even snow storms. Please see our full advised equipment list here.
The higher you climb, the more careful you will have to be of the sun’s harmful UV rays. These are strongest between 10am and 2pm, and can be a problem even in cloudy or overcast conditions. Many pieces of kit offer UV protection, especially long sleeves, broad brimmed hats and sunglasses, but high SPF sunscreen is absolutely necessary as well!
Physical exertions like trekking usually give you a healthy appetite. Unfortunately, the effects of high altitude can interfere with this, and you will not feel as hungry as you really are. As you will be using an extra 3000 calories a day, not replacing these with food can be crippling.
In order to stay in top shape, and ensure than you can finish your trek you have to eat, and eat quite a bit, whether or not you feel hungry. Carbs digest much more easily than protein at high altitudes, so eat as much of these as you can to maintain your energy levels.
If you are making a summit attempt, you won’t have time for much more than a biscuit and a hot drink during pauses. Make sure you have eaten a really hearty meal the night before, and bring a lot of small snacks with you to eat as you climb. Keep them close to hand, but make sure they don’t freeze! Keep some wrapped up in your daypack, and a few in fleece pockets under your jacket where your body heat will keep them warm.
Make sure you bring some of your favourite things to snack on. Hard candies and small chocolates are good choices. Nuts, seeds, biscuits and crisps take the extreme cold well. On the other hand, chewy bars and items containing syrup or treacle become impossible to eat when frozen.
Avoiding malaria and diarrhoea
The good news is that mosquitoes cannot survive at altitude, so there is little if any risk on the mountain itself. The bad news is that low-lying areas like Chitwan are vulnerable to malaria, and precautions should be taken. We advise Proguanil or Chloroquine tablets, and wearing long sleeves and trousers, especially between evening and morning. Use an insect repellent containing DEET on any exposed skin, apply permethrin to your clothing, and sleeping either in an air conditioned room or under a mosquito net.
Diarrhoea can be a problem for any traveller, but there are ways to minimise your risk:
Diarrhoea can have any number of causes, but it needn’t end your trek. Keep well hydrated, and drink specialised rehydration solutions like Dioralyte.
Many health professionals recommend the prescription medicine Ciproxin (ciprofloxacin) in an emergency. You should talk to your own GP about this possibility before travelling to areas where it may be needed. Most recommend a single 500mg dose for healthy adults who are not breast-feeding or pregnant.
Immodium (loperamide) is very helpful with mild cases, and we do recommend that you bring some with you.