Kilimanjaro rises from about 1,000 metres at its gates to 5,895 metres at Uhuru Peak. At the summit there is roughly half the oxygen available at sea level. The body can adapt, but it needs time, and fitness does not speed this up. This is why itinerary length matters so much.
What altitude sickness feels like
Mild acute mountain sickness (AMS) is common above about 3,000 metres. Typical signs:
- Headache, often the first sign
- Nausea or loss of appetite
- Dizziness or unusual tiredness
- Poor sleep
Mild symptoms are not unusual and often settle with rest, water and a slower pace.
Warning signs that need action
Tell your guide immediately if you notice any of these:
- A headache that gets worse or does not respond to simple painkillers
- Repeated vomiting
- Confusion, unusual behaviour, or stumbling as if drunk
- Breathlessness at rest or a wet, bubbling cough
These can be signs of serious conditions (high-altitude cerebral or pulmonary oedema). The only effective treatment is to descend, and guides are trained to make that call. Never hide symptoms to stay on the mountain.
What helps
- Go slowly ("pole pole"). Swahili for "slowly, slowly". Your guide will set a gentle pace from the first day. Follow it.
- Choose a longer itinerary. More days at altitude gives the body more time to adapt.
- Climb high, sleep low. Routes such as Machame and the Northern Circuit climb to higher ground in the day and descend to sleep.
- Drink plenty. Aim to drink regularly through the day, and drink warm fluids at camp.
- Eat, even when you are not hungry. Your body needs fuel for the climb.
- Avoid alcohol and sleeping pills on the mountain.
- Be honest about how you feel at the daily health check.
Medication
Some people take acetazolamide (often called Diamox) to help with acclimatisation. It is a prescription medicine with side effects, so speak to your doctor or a travel clinic well before your trip. Do not start a new medicine for the first time on the mountain.
Questions to ask your operator
- Are guides trained in wilderness first aid and altitude illness?
- Do they check oxygen levels and symptoms every day?
- Is emergency oxygen carried?
- What is the plan if someone needs to descend?
Travel insurance
Make sure your insurance covers trekking to 6,000 metres and emergency evacuation. Policies differ, so read the small print.
Updated 15 October 2026
