Health & Altitude

Health & Altitude

Almost all of the expeditions described in this website involve travel at high, very high or extremely high altitude.

For first-timers, it's a good idea to read-up on the effects that trekking or climbing above 2500m will have on your body and to understand the causes, symptoms and treatments for Acute Mountain Sickness.

The information on this page is a good starting point.

High Altitude

2500 - 4000m

Very High Altitude

4000 - 5500m

Extremely High Altitude


The acclimatisation process:

When you trek or climb to high altitude, your body will go through the acclimatisation process. If you climb too high too quickly you will out-strip your bodies’ ability to adjust to the increasing altitude - and this often leads to Acute Mountain Sickness.

The root cause of AMS is reduced air pressure at altitudes of 2500m and above. This makes it difficult for the lungs to ingest the oxygen in the air. Given enough time, your body will adapt to the decrease in oxygen levels at a specific altitude. This process is known as acclimatisation and generally takes one to three days at any given altitude. Whilst you body is still getting used to it, you will experience numerous symptoms. Here are some of them:

Increased heart rate and rate-and-depth of breathing (even at rest). Move slowly, particularly when walking-up steep slopes. Don't over-exert yourself. Your pulse and breathing should slow down to steady (but above 'normal') level after a day or two at altitude.

Urinary response. Altitude causes diereses which means that you'll urinate more, particularly during the night. This can lead to dehydration and disturbed sleep. Drink 3L of water each day. Consider investing in a Platypus type rehydration system. It's a good idea to take flavored drink powder to help you drink more drink more. Take a 'piss bottle' so you can relieve yourself in the comfort of your tent (rather than having to stagger out into the cold).

Periodic breathing. Above 3,000 meters most people experience periodic breathing during sleep known as Cheyne-Stokes Respirations. The pattern begins with a few shallow breaths and increases to deep sighing respirations then falls off rapidly even ceasing entirely for a few seconds. During the period when breathing stops you are likely to become restless and may wake with a sudden feeling of suffocation. This type of breathing is not considered dangerous or abnormal at high altitudes but it can leave you exhausted from lack of sleep.

Periodic breathing is very common. It usually stops after a day or so at altitude and is not an early warning for more serious medical conditions. It can be treated with the drug Acetazolamide (Diamox). Take ear-plugs, so you’re no kept awake by someone else’s periodic breathing.

Important: Sleeping tablets should not be used under any circumstances. These suppress breathing and reduce oxygen input at a time when the body is trying to take-in more, prevents acclimatization and can lead to serious health problems.

Acute Mountain Sickness

These symptoms will be experienced by almost everyone who travels to high altitude. They are not dangerous and are signs that the body is adapting to the thin air. However, the low air pressure at high altitude can cause fluids to leak from the capillaries in both the lungs and the brain which can lead to a fluid build-up and illness known as Acute Mountain Sickness. This is a particular problem for people who climb to higher altitudes without proper acclimatisation. Our gradual climbing programmes are designed to prevent AMS and ensure that we increase altitude slowly, giving people time to adapt.

In extreme cases, AMS can lead to potentially serious, even life threatening illnesses such as HACE and HAPE.

Some of the symptoms of mild AMS - and how to deal with them.

'AMS won't kill you.......but you might wish it would!' Minor AMS can leave people feeling awful. Here are some of the symptoms:

Nausea - 
Lack of appetite - 
Sleeplessness - 
Sufferers are often quiet and withdrawn from the rest of the group

If you start to suffer from AMS, it is essential that you follow the following rules in order prevent the condition from worsening.

  • Rest
  • Tell the guide
  • Treat headaches with standard pain killers.
  • Use Acetazolamide (Diamox) to help the body acclimatise better
  • Increase fluid intake
  • No further increase in altitude until the symptoms disappear (our programmes are very flexible, it is almost always possible to take an unscheduled rest day).
Do not, under any circumstances, attempt to 'tough it out' and continue higher - this WILL worsen your symptoms and jeopardise your chances of getting to the summit. In extreme cases, this may cause a medical emergency and endanger your life.

How to Avoid AMS

Altitude illness can usually be avoided by following a few golden rules, the most important being to follow a programme of SLOW ASCENT.

  • Avoid rapid ascent to altitude
  • High calorie diet (avoid added salt)
  • Keep warm (cold trekkers are more likely to develop AMS)
  • Make sure you drink at least 3L of water a day
  • Monitor your urine (should be ‘clear-and-copious’). If it yellow or orange you are dehydrated and need to drink more
  • Climb slowly, don't push too hard
  • If you are experiencing symptoms of AMS, do not increase your sleeping altitude until they have gone.

Because our mountain climbing programmes are gradual, expedition members are highly unlikely to experience anything worse that mild AMS. However, it would be a good idea to read-up on other altitude related medical problems, such a moderate/ severe AMS, HAPE and HACE before your depart.

It is also a good idea to discuss the use of the drug Acetazolamide as an aid to acclimatisation with your doctor before you depart. Use of this drug is common amongst travellers to high altitude.

Common developing-world health problems - Safe Water and Food Procedures

You will only be served bottled or boiled water on the trail. Contaminated water can cause stomach complaints that may wreck your trip. Assume that all water stream and tap water (in the developing world) is contaminated, even stream water in remote areas. Water is OFTEN/ USUALLY contaminated with Salmonella, Jardia, Bilherzia, E Coli and Crypto Speridium, all of which can cause diarrhea and infection.

Points to note:

When drinking from a stream, make sure you are close to the source, away from camp toilets and (if possible) near to a waterfall (aerated water is best).
Water must be boiled or treated with Puritabs/ Iodine

Cold water requires more treatment

Treated water tastes awful. Bring orange concentrate or similar to help you to drink more.

Cryprosperidium is a parasitic disease that causes acute diarrhoea can only be killed by boiling or the use of a UV ‘Steripen’ – there are NO OTHER ways to kill it (there are NO filter pumps, filters or chemical treatments currently on the market up to the job). It’s a very good idea to buy a Steripen if you plan to spend time in the developing world.

Other causes of diarrhea and stomach infection

Contaminated water isn't the only cause of diarrhea and stomach upsets.

Pay particular attention to personal hygiene, wound hygiene and the treatment of minor ailments.

Most travellers diarrheal infection travels via the ‘faecal-oral-route’. Wash your hands.

Bring your own wet-wipes and hand sanitizer gel. Use them after toilet stops and before meals. This is essential, and better than soap and water.
Avoid: Ice, Ice cream, Salad in all but the most hygienic of restaurants. Do not drink tap water, even for cleaning teeth and keep your mouth shut when having a shower

Treatment of diarrhea:

  • Out is good. Gets rid of the infection. Imodium is only for the bus/ plane
  • Rehydrate with Diarolyte
  • If not available, mix 8 tsp of sugar 1 tsp of salt per litre of water.
  • Bland diet (no grease); yoghurt, biscuits, bread, bananas
  • No alcohol
  • Diarrhea can be treated with a broad spectrum anti-biotic, such as Ciproflaxin. Discuss this with your doctor prior to departure.


Many of our expeditions visit areas with a malaria risk. Discuss your destination with your GP prior to departure and make sure that you have the necessary medication.

Malaria is a serious and sometimes fatal disease which is widespread in many tropical and subtropical countries. It is caught by being bitten by an infected mosquito that is carrying the malaria parasites in its saliva. Malaria occurs in over 100 countries and more than 40% of the people in the world are at risk. Large areas of Central and South America, Hispaniola, Africa, the Middle East, the Indian subcontinent, Southeast Asia and Oceania are considered malaria-risk areas

These parasites enter the host's bloodstream when bitten by an infected mosquito and then migrate to the liver where they multiply before returning back into the bloodstream to invade the red blood cells. The parasites continue to multiply inside the red cells until they burst releasing large numbers of free parasites into the blood plasma causing the characteristic fever associated with the disease. This phase of the disease occurs in cycles of approximately 48 hours.

Symptoms of malaria include fever and flu-like illness, including shaking chills, headache, muscle aches, and tiredness. Nausea, vomiting, and diarrhea may also occur. Malaria may cause anemia and jaundice (yellow colouring of the skin and eyes) because of the loss of red blood cells. Infection with one type of malaria, P. falciparum, if not promptly treated, may cause kidney failure, seizures, mental confusion, coma, and death.

For most people, symptoms begin 10 days to 4 weeks after infection, although a person may feel ill as early as 8 days or up to 1 year later. Two kinds of malaria, P. vivax and P. ovale, can relapse; some parasites can rest in the liver for several months up to 4 years after a person is bitten by an infected mosquito . When these parasites come out of hibernation and begin invading red blood cells, the person will become sick.

Avoidance of Bites

As ever, prevention is better than cure. Mosquitoes cause much inconvenience because of local reactions to the bites themselves and from the infections they transmit. Mosquito bites spread other diseases such as yellow fever, dengue fever and Japanese B encephalitis.

Mosquitoes bite at any time of day but you are most at risk in the night with most mosquito activity at dawn and dusk. If you are out at night wear long-sleeved clothing and long trousers, use a mosquito net and chemical mosquito repellent.

Mosquitoes may bite through thin clothing, so spray an insecticide or repellent on them. Insect repellents should also be used on exposed skin.

Taking Anti-Malaria Tablets

It should be noted that no prophylactic regimen is 100% effective and advice on malaria prophylaxis changes frequently. There are numerous different drugs available, none of which can defeat all malaria parasites in every malaria-prone part of the world.

The tablets you require depend on the country to which you are traveling.

Start taking the tablets before travel and continue to take them take them absolutely regularly during your stay, preferably with or after a meal and continue to take them after you have returned. This is extremely important to cover the incubation period of the disease.

In short, seek medical advice before you go. Buy the correct tablets for the county you are visiting and take them religiously and do you best to avoid being bitten.

First Aid Kit - suggested items (wilderness and altitude)

The purpose of a Travel Kit is twofold: (1) to allow the traveler to take care of minor health problems as they occur and (2) to treat exacerbations of pre-existing medical conditions.

The specific contents of the health kit are based on destination, duration of travel, type of travel, and the traveller's pre-existing medical conditions. Basic items that should be included are listed below.

Personal prescription medications (copies of all prescriptions, including the generic names for medications, and a note from the prescribing physician on letterhead stationary for controlled substances and injectable medications should be carried)
Anti malarial medications, if applicable
Anti diarrhoea medication (e.g., bismuth subsalicylate, loperamide)
Antibiotic for self-treatment of moderate to severe diarrhoea (e.g. Ciproflaxin)
Decongestant, alone or in combination with antihistamine
Paracetamol aspirin, ibuprofen, or other medication for pain or fever
Mild laxative
Throat lozenges
Antifungal and antibacterial ointments or creams
1% hydrocortisone cream
Epinephrine auto-injector (e.g., EpiPen), especially if history of severe allergic reaction.
Medication for treatment and prevention of AMS (e.g. Diamox).
Other Important Items
Insect repellent containing DEET (up to 50%)
Sunscreen (preferably SPF 30 or greater)
Aloe gel for sunburns
Digital thermometer
Oral re-hydration solution packets
Basic first-aid items (adhesive bandages, gauze, ace wrap, antiseptic, tweezers, scissors, cotton-tipped applicators)
Antibacterial hand wipes or alcohol-based hand sanitizer
Plasters for blisters (e.g. Compede)
Lubricating eye drops (e.g. Natural Tears)
First Aid Quick Reference card
Water purification tablets