Quick answer: Altitude sickness is the main reason climbers fail to reach Kilimanjaro’s summit. It happens when you go up faster than your body can adjust to the thinner air. The best protection is simple: choose a longer route, walk slowly, drink plenty of water and tell your guide honestly how you feel.
This article is general information, not medical advice. Talk to your doctor before your climb, especially if you have heart or lung conditions.
What is altitude sickness?
Above about 2,500 metres, each breath contains less oxygen. Kilimanjaro’s summit, Uhuru Peak, is 5,895 metres high. Most climbers feel the altitude in some way. Acute Mountain Sickness (AMS) is the common, mild form. In rare cases it can develop into serious conditions affecting the lungs (HAPE) or the brain (HACE), which need immediate descent.
What are the symptoms?
Mild (common): headache, tiredness, poor appetite, mild nausea, trouble sleeping. These often improve with rest, water and a slower pace.
Serious (rare, needs descent straight away):
- Confusion, clumsiness or difficulty walking in a straight line
- Breathlessness even at rest, or a wet cough
- Severe headache that does not improve with painkillers
- Extreme drowsiness
Who gets it?
Anyone can. Fitness does not protect you, and very fit climbers sometimes go too fast and suffer more. Age and gender make little difference. How quickly you climb matters most.
How do I reduce the risk?
- Take more days. A 7- or 8-day route gives your body time to adjust. Our 8-day Lemosho and 7-day Machame routes are built for this.
- Go “pole pole”. That means “slowly, slowly” in Swahili. You will hear your guides say it all day.
- Climb high, sleep low. Routes like Machame climb to Lava Tower, then drop to camp for the night.
- Drink 3 to 4 litres of water a day and keep eating, even when you are not hungry.
- Avoid alcohol and sleeping pills on the mountain.
- Ask your doctor about Diamox (acetazolamide). Many climbers use it to help acclimatisation, but only on medical advice.
How do guides monitor climbers?
Good mountain crews check climbers every day: how you feel, your appetite and often your oxygen level and pulse with a pulse oximeter. The most important thing you can do is be honest. Hiding a headache to “push on” is how small problems become serious ones. If someone needs to go down, an experienced guide will take them down. Going down is the cure.
Does altitude sickness affect safaris?
Not really. Most safari areas are at moderate altitude. The Ngorongoro Crater rim is about 2,300 metres, so you might feel slightly breathless climbing stairs, but nothing more. If you are combining a climb and a safari, do the safari first. It is a gentle way to start, and you will rest afterwards on the Zanzibar beach.
Questions about your fitness or route choice? Talk to us. Also read how much it costs to climb Kilimanjaro and our Kilimanjaro packing list.
