Acute Mountain Sickness (AMS)- How to avoid altitude sickness on Kilimanjaro

Acute Mountain Sickness is what medical people call altitude or mountain sickness; “acute” simply means that the onset is sudden. AMS symptoms do not last, and, if mild or moderate, may disappear if the victim rests or ascends no further; if they are severe, the victim must descend. Most people who attempt Kilimanjaro have invested a lot of time and money, so the stakes are high. Learn to recognise whether AMS is mild, moderate or severe.
Mild AMS feels like a hangover and can affect people at any altitude above 7000 feet or even lower. Its commonest symptom is a headache (which should respond to aspirin, paracetamol or ibuprofen) combined with atleast one of the following:

feeling sick
lack of appetite
difficulty sleeping
general malaise (feeling lousy, lacking energy)

Moderate AMS differs from mild in that

there is likely to be vomiting
the headache does not respond to pain relief
the victim may be very short of breath even when not exercising (eg after 15 minutes’ rest)

Mild AMS is bearable, and affects most people who attempt Kilimanjaro to a greater or lesser extent. Moderate AMS can be seriously unpleasant, and some sufferers have to give up. Although symptoms may clear if there is no further ascent, very few Kilimanjaro trips have the flexibility to allow individuals prolonged rest or to postpone the summit attempt. In practice the choice tends to be simple: continue the ascent or descend.
Severe AMS is different again:

there is ataxia – the word medical people use to describe loss of muscular co-ordination and balance, as when somebody stumbles, staggers or falls
there may be altered mental states, such as confusion, aggression or withdrawal
it may lead to fluid leakage into the brain and/or lungs
if untreated, it can cause coma followed by death

However, there are many other causes of ataxia, such as extreme fatigue, hypothermia, dehydration and low blood suger. Get the suspected victim to have a short rest, a drink, and a snack, and put on extra clothing if need be; this should take care of other possible causes. If symptoms persist, or if there is mental confusion and/or extreme shortness of breath while at rest, suspect severe AMS.

Severe AMS is avoidable and treatable, but only if you are aware of the possible risks an look out for yourself and others. Most of your group will have mild AMS at some stage of the walk, but anyone with moderate AMS should be monitored closely in case they worsen. Assess the sufferer’s condition first thing in the morning; symptoms that persist after resting should be taken seriously. Severe AMS should be treated by immediate descent, oxygen and suitable drugs.

If you are unlucky enough to have moderate to severe AMS, you will probably feel so ill that you no longer care about reaching the summit. Occasionally, because the stakes are so high, some very determined individuals play down on even deny their symptoms and want to struggle on. The problems is that AMS has affected their judgement, and they do not realise how ill they have become. In such cases the guide or group leader may instruct them to descend, and his or her decision is final. If you are on the trip with a friend, you will know that person better than the group leader can, so you can help the decision process.
If you and your group act on the advice given so far, you are very unlikely to meet other complications from AMS

Does Diamox prevent AMS?
Many drugs have been tired in the treatment and prevention of AMS. The research literature is large and contains some conflicting conclusions.
Your blood has to maintain a finely tuned balance for bodily function to work well. When you hyperventilate (pant), as when over-exerting at altitude, you lose a lot of carbon dioxide which can reduce the acidity of your blood. Diamox blocks or slows the enzyme involved in converting carbon dioxide. As a result, it speeds up acclimatisation by stopping the blood from becoming too alkaline and by smoothing out your breathing; it also reduces periodic breathing. Many people who attempt Kilimanjaro take Diamox with them because it can help to prevent, as well as treat, AMS. Before rushing off to get a doctor’s prescription, however, consider the possible side-effects.
Diamox has been known to cause severe allergic reactions in a few individuals. So you should try it out ahead of your trip to test if you are allergic, to experiment with dosage and to discover whether you can tolerate the side-effects which may include:

increased flow of urine (diuresis)
Numbness or tingling in hands, feet and face
Nausea
Finding that carbonated drinks taste flavor

Since altitude has a diuretic effect anyway, many people prefer to avoid Diamox, wishing to avoid further interruptions to sleep in order to urinate. This may be a problem when dosage is too high; individuals vary so much that you may have to establish your own dosage; not easy if Kili is your first high-altitude trek.

How to prevent and manger AMS

prepare well by becoming fitter (and giving up smoking)
take suitable supplies and pack your gear for easy retrieval
Avoid over-exertion: if possible ascend slowly enough that you can still breathe through your nose
Avoid sleeping pills and alcohol on the mountain
Eat small amounts of food often, even if you don’t feel hungry; avoid excessive salt
Drink plenty of fluids (four to five litres per day), especially water
If you plan to use Diamox, experiment with dosage well ahead of time under medical supervision
Do not deny any symptoms you may experience and keep the group leader or guide informed.