Altitude Sickness

Altitude sickness is a common problem affecting travellers to high places (see below).

The physiological response to high altitude is an increase in rate and depth of respiration. Sometimes this adaptation does not occur and problems arise. This is called Acute Mountain Sickness or AMS. Two types are described. In the benign form the symptoms include headache, nausea, a loss of appetite, sleep disturbance and occasionally vomiting. Unfortunately, these symptoms are non-specific and might also describe a bad case of food poisoning. Travellers are advised against travel to a higher altitude if these symptoms are present. Symptoms may disappear within a couple of days at a given altitude allowing a further attempt to ascend gradually. If symptoms are troublesome, it is better to descend to see if this makes a difference. Just 500 metres may help. Serious malignant AMS can be life threatening whereby fluids accumulate in the lungs or brain.

In all forms of AMS speed of ascent is the major factor responsible. It is unusual to see AMS below 2700m, but it is possible. Those travelling to altitudes higher than 2400 metres are advised to ascend no more than 300 metres a day and to have a rest day after every 1000 metres attained. Most organised tours stay within these guidelines. People undertaking self-organised treks are most at risk.

Remember the Four Golden Rules to avoid life threatening illness.

• Understand and recognize the symptoms of acute mountain sickness (AMS).
• Never ascend with symptoms of AMS.
• Descend if the symptoms get worse despite having stayed at the same altitude for a period.
• Keep a close eye on fellow trekkers

The medication acetazolamide (Diamox) can be used to prevent or treat mild altitude sickness, especially the symptoms of headache and insomnia. Diamox may be started the day before ascent, upon reaching 2700 metres or when symptoms become troublesome.

Acetazolamide** 250 mg tablets. = Diamox

Adult Dosage: Take half a 250-mg tablet i.e.125mg twice a day (breakfast and lunch).

Possible side effects are increased urination, tingling in the fingers or toes, loss of appetite, a flat taste to carbonated drinks, and decreased exercise tolerance. Do not take this drug if you are allergic to sulfa drugs. NB: DESCENT remains the best cure for altitude sickness.