High Altitude Medicine

In 1991 some doctors interested in mountain medicine saw a young, fit climber die on the Mera La. The doctor with him knew little about the risks of severe altitude mountain sickness. The tragedy inspired the doctors to study altitude illness and share this information with others.

Since the early 1990s members of Medical Expeditions have, along with others, been busy studying mountain medicine. They have done their best to improve the knowledge of doctors responsible for, or advising, people travelling at altitude.

This section looks at the effects that travelling at altitude can have on your body and aims to help you to understand why you may not feel well or get ill. It suggests ways to avoid illness and suggests what you should do if you get an altitude related illness. Our own experiences and real cases have been used as examples. The deaths on the Mera La were caused by going to high altitude, but both could have been avoided had simple rules been followed.

The following is a brief look at the fascinating study of High Altitude Medicine. This information is only meant as a rough guide to help you prepare for and have a safe, fun amd exciting trip in the Himalayas.

ACCLIMITIZATION TO HIGH ALTITUDE

When the body slowly adapts to lower oxygen levels the process is called acclimatisation. Different people acclimatise at different speeds, so no rule works for everyone, but there are good guidelines.

  • Over 3,000m go up slowly, sleeping no more than 300m higher at the end of each day. Going higher during the day is ok as long as you go down to sleep (“walk high – sleep low”). If you go up higher and can’t descend – take a rest day to allow your body time to ‘catch up’. This may seem very slow, and some people will comfortably be able to go up much faster, but in a group someone will always be the slowest to acclimatise – and the timetable should be made to keep them healthy.
  • A rest day scheduled after every 2 to 3 days will also help.
  • Driving or flying to high altitude means more people will suffer from AMS. It is really sensible to find out about the height of your planned route before you travel. Better still, make a drawing to show the height that you will sleep at each night. If you don’t know – ask. There’s no better way to spot the days which are likely to cause altitude illness.

ACCUTE MOUNTAIN SICKNESS (AMS)

The common symptoms for AMS are:

  • Headache.
  • Nausea (feeling sick)
  • Vomiting (being sick)
  • Fatigue (feeling tired)
  • Poor appetite (not hungry)
  • Dizziness
  • Sleep disturbance

It’s good if everyone logs how they feel while travelling and is honest with others in the group, especially the guides. Everyone can help make decisions – to go up, to have a rest day, or to go down. As a group, everyone’s health and happiness is equally important.

Hiding illness or pushing someone on could be fatal. Some people just seem to acclimatise slowly, and need to take things more gently. If you are unfit, it doesn’t mean you are more likely to suffer, but overdoing it might be risky. If you are unused to exercise, feeling tired while trekking is not surprising.

Similarly if you are sleeping in a tent every night and are not used to it, your sleep may be poor. The food may also be very different.

The most important thing is: are the symptoms getting better or worse?

If you think you are getting worse – walk down (at least 500 to 1,000m lower for sleeping). Give your body extra time to acclimatise. Don’t leave this decision until it’s too late. The drug acetazolamide (trade name Diamox) can be used to reduce the effects of AMS, useful where large height gains are unavoidable. It does have side effects, and some people can be allergic to it.

HIGH ALTITUDE CEREBRAL OEDEMA (HACE)

The brain is affected by altitude because it needs a good supply of oxygen and may swell causing pressure. High Altitude Cerebral Oedema (HACE) is caused by brain swelling and can kill very quickly if not treated.

SOME COMMON SYMPTOMS OF HACE:

  • Headaches – very common at altitude, especially if you suffer headaches or migraine at home.
  • Loss of balance – co-ordination and balance may be affected. Older people and those who are acclimatised feel less effect.
  • Clumsiness’ and bad judgements increase the risk of accidents.
  • Mood changes – on a ‘trip of a lifetime’ there will be good days and bad days. Bad days can trigger disappointment and depression. Be prepared for mood swings!

BEFORE YOU GO:

  • Learn the signs of HACE & stroke.
  • Prepare medical supplies.
  • Consider expectations / fears and who will support you on bad days.

AT ALTITUDE:

  • Headache (AMS) avoid triggers – dehydration, exhaustion, alcohol – treat with painkillers.
  • Stroke – treat with ½ a 300mg aspirin & descend. See a doctor.
  • Be honest about how you feel.

CONSEQUENCE IF IGNORED:

Loss of consciousness – confusion, drowsiness. Reduced breathing. DEATH. In serious cases death can occur within as little as an hour of symptoms being noticed.

DESCEND DESCEND DESCEND DESCEND

People do go to high altitudes with pre-existing medical conditions. If you suffer from a condition, you must talk to your doctor about whether or not you should go to high altitude and, if you do, how you should take care of yourself. With any condition there is more risk to health when travelling to remote locations. The key is to lower this risk as far as possible. Be prepared to give up part or all of your trip for safety reasons.

PRE EXISTING MEDICAL CONDITIONS AND HIGH ALTITUDE

BEFORE YOU GO TO HIGH ALTITUDE:

  • See your doctor / specialist at least 6 months before your trip. Find out about the risks your condition poses for travel at high altitude.
  • Make a medical plan and what, if any, support you will need. Find out what medical help may be available. Think about what you will do if things go wrong.
  • Make a contacts list for your condition for home & where you are going.
  • Make your guides & support staff aware of your medical condition, the signs, symptoms and treatment. Your illness could affect everyone in your group.
  • Get first aid / medical training for yourself and others if necessary.
  • Make a kit with your medicines. Make clear labels and instructions. Have spare supplies and split the kit between people to lower the chance of losing it all.
  • Ask your doctor to prepare an official letter, explaining your condition, treatment and contact details (translate if necessary).
  • Tell your travel nurse about your conditions before vaccinations, etc.
  • Get medical insurance that covers your condition and the risks of the trip. It can be hard, very expensive or impossible to cover what some people want.

CARING FOR YOURSELF AT ALTITUDE:

  • Always carry your medical information letter / MedicAlert bracelet.
  • Each day, write down medicines taken and any changes in your condition. Please keep your guide up to date.
  • If symptoms worsen avoid further ascent, consider the possibility of altitude related illnesses and descend as necessary.
  • Be honest with everyone about changes in your medical condition.

    • Look after your family, friends and other travellers.

THE EFFECTS OF HIGH ALTITUDE

Most people going high have to deal with altitude related illnesses. Dealt with correctly, they are unlikely to be a major problem. Dealt with incorrectly they can be disastrous – spoiling the trip for the person who is ill and those with them.

Being honest about how you feel each day can make a difference, and knowing what’s happening to you could save your life. Some very strange things can happen to your body when you go high!

Most people who have been to altitude can tell you about having headaches, being out of breath, sleeping badly and not feeling hungry. These are symptoms of AMS. AMS is uncomfortable, not life threatening. If the AMS symptoms become severe and you keep going higher – fluid in the brain (High Altitude Cerebral Oedema – HACE) or fluid in the lungs (High Altitude Pulmonary Oedema – HAPE) can happen and these can kill you very quickly. What people don’t know about is that you’ll need to pee more, your balance may become unsteady, your eyesight could change and your nails will grow differently.

Finding out about what your body is doing as it goes higher is fascinating and can become part of the fun of travel! In fact, when you think how clever your body is at dealing with such big changes, you may even want to know more!