What are common symptoms of altitude sickness when climbing Kilimanjaro?

When climbing Kilimanjaro, trekkers will often feel shortness of breath and moderate altitude sickness due to the high altitude, even if they are going at a relatively modest pace. Headaches, nausea, and dizziness are other frequent altitude sickness symptoms while climbing Kilimanjaro. Insomnia and loss of appetite are also frequent. Blurred vision, confusion, and the inability to move are among the more severe symptoms. If such symptoms appear, you must descend immediately with the assistance of your guide to avoid more serious and long-term effects.

Altitude sickness, also called Acute Mountain Sickness (AMS), occurs when your body doesn’t adapt quickly enough to the lower oxygen levels above ~2,500–3,000 m. Most climbers will experience at least mild symptoms on Kilimanjaro.

Common Mild Symptoms (Very Frequent)

Headache — the most common first sign
Fatigue or unusual tiredness
Dizziness or light-headedness
Nausea or loss of appetite
Shortness of breath (especially with exertion)
Difficulty sleeping or restless sleep
Mild swelling of hands, feet, or face

These often start above 3,000–4,000 m and are usually worse at night.

More Serious Symptoms (HAPE or HACE — Seek Immediate Help)

Severe headache that doesn’t improve with rest or medication
Persistent vomiting
Extreme fatigue or inability to walk straight (ataxia)
Shortness of breath even at rest
Wet cough or frothy sputum (possible High Altitude Pulmonary Edema – HAPE)
Confusion, hallucinations, or changes in behavior (High Altitude Cerebral Edema – HACE)
Loss of coordination or inability to perform simple tasks

What to Do If Symptoms Appear

Tell your guide immediately — don’t try to “push through.”
Rest, hydrate, and eat light carbs.
Descend if symptoms worsen or don’t improve.
Medications like Diamox (acetazolamide) can help prevent or reduce symptoms (consult a doctor beforehand).