Altitude sickness is the biggest challenge on Kilimanjaro. It can affect anyone, regardless of age or fitness. Understanding it — and choosing the right itinerary — is the best way to stay safe and reach the summit.
What is altitude sickness?
As you climb higher, the air pressure falls and each breath contains less oxygen. Your body needs time to adapt. If you climb too fast, you may develop Acute Mountain Sickness (AMS).
Common symptoms
- Headache
- Nausea or loss of appetite
- Dizziness
- Tiredness and poor sleep
- Shortness of breath when exercising
Mild symptoms are common above about 3,000 m and often improve with rest, fluids and time.
Serious forms
In rare cases, altitude sickness can develop into:
- HAPE (high-altitude pulmonary oedema) — fluid in the lungs, causing breathlessness at rest and a persistent cough
- HACE (high-altitude cerebral oedema) — swelling of the brain, causing confusion, loss of coordination and severe headache
Both are medical emergencies. The treatment is immediate descent.
How to prevent altitude sickness
- Choose a longer route. Seven or eight days greatly improves acclimatisation.
- Go "pole pole" (slowly, slowly). Your guide sets a steady pace.
- Climb high, sleep low. Routes like Machame and Lemosho include this naturally.
- Drink plenty of water — around 3–4 litres a day.
- Eat well, even if you do not feel hungry.
- Avoid alcohol and sleeping pills on the mountain.
- Speak to your doctor about preventive medication before your trip.
How we keep you safe
- Twice-daily health checks with a pulse oximeter to measure oxygen levels and heart rate
- Guides trained to recognise AMS, HAPE and HACE
- Emergency oxygen carried on every climb
- Clear rules: if a climber shows serious symptoms, they descend with a guide
- Travel insurance covering helicopter evacuation is required
How altitude affects the body
At Kilimanjaro's summit there is roughly half the oxygen available at sea level. Your body responds by breathing faster, increasing heart rate and, over several days, producing more red blood cells. This process — acclimatisation — takes time, which is why the number of days on the mountain matters so much.
Daily routine for staying healthy
- Walk slowly and breathe steadily
- Drink regularly throughout the day
- Eat every meal, even small portions
- Take part in short acclimatisation walks in the afternoon
- Report any symptoms honestly at health checks
Who is at risk?
Anyone can be affected. Fitness does not protect you — in fact, very fit climbers sometimes walk too fast. Previous good experience at altitude helps but is not a guarantee.
Frequently asked questions
Will I definitely get altitude sickness?
Many climbers experience mild symptoms like headaches or poor sleep. Serious altitude sickness is much less common, especially on longer routes with good guiding.
Can altitude sickness be treated on the mountain?
Mild symptoms can be managed with rest and fluids. For moderate or severe symptoms, the only reliable treatment is to descend.
Should I take medication to prevent it?
Some climbers use preventive medication. Only take it on the advice of your doctor, who can explain the benefits and side effects.
Honest advice
Reaching the summit is a wonderful goal, but your health matters most. Listen to your body, tell your guide how you feel and trust their judgement.
Read more about choosing a route or explore our Kilimanjaro climbing tours.
Utmost Tanzania Tours
Utmost Tanzania Tours is an Arusha-based tour operator specialising in tailor-made wildlife safaris, Mount Kilimanjaro treks, Zanzibar beach holidays and cultural tours.
