Around 75% of climbers on Kilimanjaro experience some symptoms of altitude sickness above 3,000 metres. That number should not frighten you — mild symptoms are a normal part of climbing at altitude, and most people manage them and reach the summit. What matters is knowing the difference between normal and dangerous.
What altitude sickness actually is
When you ascend quickly, your body does not have enough time to produce the extra red blood cells it needs to carry oxygen efficiently at altitude. The result is a cluster of symptoms that climbers know well: headache, nausea, fatigue, poor sleep, and a vague feeling that something is wrong.
This is Acute Mountain Sickness (AMS), and it is your body asking for more time. It is not weakness. It is not a sign that you should not be on the mountain. It is a signal to slow down.
More serious forms exist. High Altitude Cerebral Edema (HACE) is a swelling of the brain that can cause confusion, loss of coordination, and — if ignored — unconsciousness. High Altitude Pulmonary Edema (HAPE) is a build-up of fluid in the lungs that makes breathing laboured, even at rest. Both are rare on Kilimanjaro. Both are life-threatening if not treated immediately by descending.
HACE and HAPE are not inconveniences — they are emergencies. If anyone in your group shows confusion, loss of coordination, or breathlessness at rest, the answer is descent. Not rest. Not Diamox. Descent — immediately, regardless of how close the summit is.
Symptoms to know
Mild AMS — monitor carefully
- Headache (especially on waking)
- Nausea or loss of appetite
- Fatigue beyond what the day's walking explains
- Dizziness on standing
- Poor or restless sleep
These are common above 3,500m. Rest, hydrate, and do not ascend until they ease.
Serious symptoms — descend immediately
- Confusion or disorientation
- Difficulty walking in a straight line
- Persistent dry cough, especially at night
- Breathlessness at rest
- Lips or fingertips turning blue
If you or anyone in your group shows these signs, the only treatment is descent. Not rest. Not Diamox. Descent — immediately, regardless of time of day.
How to prevent it
Go slow. Pole pole is not a Swahili pleasantry — it is the core strategy. Your body acclimatises at its own pace and cannot be hurried. The climbers who push hardest on day one are often the ones who turn back on day four.
If you feel a headache coming on above 3,500m, stop and rest before going higher. Ascend only when the headache has cleared — not when it has eased.
Choose a longer route. A seven-day Machame or Lemosho gives your body two to three extra nights to adapt compared to a five-day Marangu. This single choice has more impact on your summit odds than your fitness level.
Drink three to four litres of water per day. Dehydration makes AMS symptoms worse and is easy to avoid. Drink before you feel thirsty.
Sleep low, climb high. Good routes build in acclimatisation days where you ascend to a higher point, then descend to sleep lower. The Machame route's detour to Lava Tower (4,630m) before dropping to Barranco Camp (3,960m) is a deliberate acclimatisation strategy, not an inefficiency.
Diamox (acetazolamide). This prescription medication helps your body breathe faster and process altitude more efficiently. Many climbers use it; many do not. Discuss it with your doctor before you travel. It does not mask symptoms — it genuinely helps your physiology adapt — but it is not a substitute for a sensible ascent rate.
No alcohol above 3,000m. It dehydrates you and disrupts the quality of sleep your body needs to recover each night.
What our guides watch for
Every Sindee guide is trained in wilderness first aid and high-altitude medicine. We carry pulse oximeters and check blood oxygen levels at every camp. A reading below 70% at altitude is a serious warning sign.
We will tell you honestly how you are doing. We have turned groups around before — and we will again if we need to. No summit is worth a life, and no guide worth his boots will let pride get in the way of that decision.
We have seen strong, fit climbers struggle badly above 4,000m and fragile-looking first-timers walk to Uhuru Peak as if it were a Sunday stroll. Altitude does not care about your marathon times. What it respects is patience.
I have turned groups around at 5,200 metres. It is never an easy conversation. But every one of those climbers came back a second time — more prepared, more patient, more honest with themselves. Most of them reached the summit. The mountain is forgiving if you respect it. — Baraka Shoo, Kilimanjaro guide
Pole pole. That is the medicine.