Acute mountain sickness, more commonly known as altitude sickness, is the single biggest killer on Kilimanjaro. This may surprise a few people who, given the large number of trekkers who climb Kilimanjaro each year, are under the mistaken impression that Africa’s highest mountain is also a safe mountain. Unfortunately, as any mountaineer will tell you, there’s no such thing as a safe mountain, particularly one nearly 6000m tall with extremes of climate near the summit and ferociously carnivorous animals roaming the lower slopes.
Your biggest enemy on Kilimanjaro, however, is likely to be neither the weather nor the wildlife but the altitude. Unsurprisingly, KINAPA are shy about revealing how many trekkers perish on Kili each year but what is known is that, during the millennium celebrations, when the mountain was swamped by more than a thousand trekkers on New Year’s Eve alone, three died and thirty-three more had to be rescued.
The authorities are doing what they can to minimize the number of deaths: guides are given thorough training in what to do if one of their group is showing signs of altitude sickness and trekkers are required to register each night upon arrival at the campsite and have to pay a US$20 ‘rescue fee’ as part of their park fees.
But you too can do your bit, by avoiding AMS in the first place. The pages in this section discuss in detail what AMS actually is, how it is caused, the symptoms and, finally, how to avoid it. Read this section carefully: it may well save your life.
The percentage of oxygen in the atmosphere at sea level is about 21%. As altitude increases, the percentage remains the same but the number of oxygen molecules per breath is reduced. At 12,000 feet (3,600 m) there are roughly 40% fewer oxygen molecules per breath so the body must adjust to having less oxygen. Altitude sickness, known as AMS, is caused by the failure of the body to adapt quickly enough to the reduced oxygen at increased altitudes. Altitude sickness can occur in some people as low as 8,000 feet, but serious symptoms do not usually occur until over 12,000 feet.
Mountain medicine recognizes three altitude categories:
In the first category, high altitude, AMS and decreased performance is common. In the second category, very high altitude, AMS and decreased performance are expected. And in extreme altitude, humans can function only for short periods of time, with acclimatization. Mount Kilimanjaro's summit stands at 19,340 feet - in extreme altitude.
At over 10,000 feet (3,000 m), more than 75% of climbers will experience at least some form of mild AMS.
There are four factors related to AMS:
The main cause of altitude sickness is going too high (altitude) too quickly (rate of ascent). Given enough time, your body will adapt to the decrease in oxygen at a specific altitude. This process is known as acclimatization and generally takes one to three days at any given altitude. Several changes take place in the body which enable it to cope with decreased oxygen:
AMS is very common at high altitude. It is difficult to determine who may be affected by altitude
sickness since there are no specific factors such as age, sex, or physical
condition that correlate with susceptibility. Many people will experience mild AMS
during the acclimatization process. The symptoms usually start 12 to 24
hours after arrival at altitude and will normally disappear within 48 hours.
The symptoms of Mild AMS include:
Symptoms tend to be worse at night and when respiratory drive is decreased. Mild AMS does not interfere with normal activity and symptoms generally subside as the body acclimatizes. As long as symptoms are mild, and only a nuisance, ascent can continue at a moderate rate.
While hiking, it is essential that you communicate any symptoms of illness immediately to others on your trip.
signs and symptoms of Moderate AMS include:
Normal activity is difficult, although the person may still be able to walk on their own. At this stage, only advanced medications or descent can reverse the problem. It is important to get the person to descend before the ataxia reaches the point where they cannot walk on their own (which would necessitate a stretcher evacuation). Descending only 1,000 feet (300 m) will result in some improvement, and 24 hours at the lower altitude will result in a significant improvement. The person should remain at lower altitude until all the symptoms have subsided. At this point, the person has become acclimatized to that altitude and can begin ascending again.
AMS results in an increase in the severity of the aforementioned symptoms
Severe AMS requires immediate descent of around 2,000 feet (600 m) to a lower altitude. There are two serious conditions associated with severe altitude sickness; High Altitude Cerebral Edema (HACE) and High Altitude Pulmonary Edema (HAPE). Both of these happen less frequently, especially to those who are properly acclimatized. But, when they do occur, it is usually in people going too high too fast or going very high and staying there. In both cases the lack of oxygen results in leakage of fluid through the capillary walls into either the lungs or the brain.
HAPE results from fluid build up in the lungs. This fluid prevents effective oxygen exchange. As the condition becomes more severe, the level of oxygen in the bloodstream decreases, which leads to cyanosis, impaired cerebral function, and death. Symptoms of HAPE include:
Confusion, and irrational behavior are signs that insufficient oxygen is reaching the brain. In cases of HAPE, immediate descent of around 2,000 feet (600 m) is a necessary life-saving measure. Anyone suffering from HAPE must be evacuated to a medical facility for proper follow-up treatment.
is the result of the swelling of brain tissue from fluid leakage. Symptoms
of HACE include:
This condition is rapidly fatal unless the afflicted person experiences immediate descent. Anyone suffering from HACE must be evacuated to a medical facility for follow-up treatment.
The following are recommended to achieving acclimatization:
Our guides are all experienced in identifying altitude sickness and dealing with the problems it causes with climbers. They will constantly monitor your well-being on the climb by watching you and speaking with you. Twice daily, our guides will conduct tests with a pulse oximeter to measure your oxygen saturation and pulse rate. Additionally, our guides will administer the Lake Louise Scoring System (LLSS) to help determine whether you have any symptoms of altitude sickness and the severity.
It is important that you be open, active and honest with your guide. If you do not feel well, do not try to pretend you are fine. Do not mask your symptoms and say you feel OK. Only with accurate information can your guide best treat you.
Of course, there is always the chance that you will have to abandon your climb. In these situations, the guide will tell you to descend. It is not a request, but an order. The guide's decision is final. Do not try to convince him with words, threats or money to continue your climb. The guide wants you to succeed on your climb, but will not jeopardize your health. Respect the decision of the guide.
Our guides will use a pulse oximeter to measure the oxygen level in your blood and your pulse rate in the morning and evening. The oximeter is placed on a climber's fingertip. The oximeter uses two beams of light that shine into small blood vessels and capillaries in your finger. The sensor reflects the amount of oxygen in the blood.
Oxygen saturation is a measurement of how much oxygen your blood is carrying as a percentage of the maximum it could carry. Normal blood oxygen levels at sea level are 95-100%.
We carry bottled oxygen on all of our climbs as a precaution and additional safety measure. The oxygen cannister is for use only in emergency situations. It is NOT used to assist clients who have not adequately acclimatized on their own to climb higher. The most immediate treatment for moderate and serious altitude sickness is descent. With Kilimanjaro's routes, it is always possible to descend, and descend quickly. Therefore, oxygen is used strictly to treat a stricken climber, when necessary, in conjunction with descent, to treat those with moderate and severe altitude sickness. We are aware that some operators market the use of supplementary personal oxygen systems as a means to eliminate the symptoms of AMS. To administer oxygen in this manner and for this purpose is dangerous because it is a temporary treatment of altitude sickness. Upon the cessation of the use of oxygen, the client will be at an even higher altitude without proper acclimatization.
99% of the companies on Kilimanjaro do NOT offer supplementary oxygen - because it is potentially dangerous, wholly unnecessary and against the spirit of climbing Kilimanjaro. The challenge of the mountain lies within the fact that the summit is at a high elevation, where climbers must adapt to lower oxygen levels at altitude. Using supplementary oxygen is akin to putting the mountain at sea level, where nearly everyone can summit
Large, one-wheeled rescue stretchers are found on Mount Kilimanjaro but they are only available within a small area of the park. That means that if a climber is unable to walk due to severe altitude sickness or a leg injury that compromises mobility, getting that climber down the mountain could pose difficult challenges for Kilimanjaro operators. Usually it means assisting the injured climber by carrying him or her on one's back.
At The Peak of Africa and below, we carry a portable stretcher at all times in case of emergencies when a climber is unable to walk on their own and the trekking party is some distance away from the park's stretchers. Our portable stretchers are compact, strong and lightweight. The device can be used to evacuate an injured climber quickly off the mountain. To use, the subject is secured to the stretcher using straps. Then porters hold on to the hand grips to usher the climber to safety.
At 9,800 feet (3,000 m), the Gamow Bag can simulate a descent of 4,800 feet (1,500 m). After two hours in the bag, the person's body chemistry will have "reset" to the lower altitude. This acclimatization lasts for up to 12 hours outside of the bag which should be enough time to get them down to a lower altitude and allow for further acclimatization.
Our staff does not carry Gamow bags. Use of a Gamow bag on Mount Kilimanjaro is impractical because descent is the most immediate, accessible treatment.