Altitude Sickness on the Roof of Africa: Prevention and Treatment for Safari Travellers

Medically reviewed by Prof. Giorgi Pkhakadze, MD, MPH, PhD — Professor of Public Health, David Tvildiani Medical University.

Kenya and Ethiopia sit across the East African Rift, a landscape of dramatic altitude variation. Visitors travelling from sea level to the Ethiopian Highlands or to the slopes of Mount Kenya can gain more than 3,000 metres within a single day of flying, creating the ideal conditions for altitude-related illness. Understanding the physiology, the symptoms and the prevention strategies means your safari remains a health experience rather than a medical emergency.

How Altitude Affects the Body

At altitude, atmospheric pressure drops and the partial pressure of oxygen falls with it. Your body responds by breathing faster and deeper, increasing heart rate and, over days, producing more red blood cells. In the short term, however, oxygen delivery to tissues is reduced. The brain, lungs and muscles are most sensitive. Acute Mountain Sickness (AMS) typically begins 6–12 hours after arrival at altitude above 2,500 metres and resolves within 24–48 hours if you ascend no further.

The two dangerous complications — High-Altitude Pulmonary Oedema (HAPE) and High-Altitude Cerebral Oedema (HACE) — are medical emergencies. HAPE involves fluid accumulating in the lungs; HACE involves swelling of the brain. Both can progress from first symptoms to death within hours if descent is not immediate.

Africa Calling Safaris client survey (2019–2024): Among travellers who included Ethiopia or the Mount Kenya region in their itinerary, 41% reported at least one symptom consistent with Acute Mountain Sickness. Of those, fewer than 15% had been briefed by their travel clinic on altitude prophylaxis before departure.

Recognising Acute Mountain Sickness

The Lake Louise Score is the clinical standard for diagnosing AMS. A score of 3 or above in the context of a recent ascent indicates AMS. The key symptoms are headache (required for diagnosis), fatigue or weakness, dizziness or light-headedness, difficulty sleeping, and loss of appetite or nausea. If you experience a new headache within 24 hours of arrival at altitude and it is accompanied by any of those other symptoms, treat it as AMS. Rest at the same altitude, hydrate well and take ibuprofen or paracetamol for the headache. Do not ascend further until you are symptom-free for 24 hours.

Prevention: Practical Steps Before and During Travel

The most important prevention is itinerary design. If your route includes altitudes above 2,500 metres, build in at least one acclimatisation night at an intermediate elevation. Flying directly from Nairobi (1,700 m) to Addis Ababa (2,355 m) and then immediately travelling by road to the Bale Mountains (3,000–4,000 m) the next day is too fast for most travellers. A rest day in Addis before ascending is strongly advisable.

Acetazolamide (Diamox) is the most evidence-based pharmacological prevention. It works by stimulating breathing, speeding acclimatisation. The standard regimen is 125–250 mg twice daily, starting 24 hours before ascent. It is a prescription medication in most countries and should be discussed with a travel medicine physician. Common side effects include increased urination and tingling in the fingers and toes. It is contraindicated in people with sulfa drug allergy.

Emergency Protocol: When to Descend Immediately

Descent is the only reliable treatment for HAPE and HACE. The rule is simple: if any of the following symptoms appear, descend immediately and seek emergency medical care — do not wait until morning, do not try to sleep it off. The symptoms are: confusion, loss of coordination or inability to walk a straight line (HACE), severe breathlessness at rest, a persistent cough producing pink or frothy sputum (HAPE), or chest tightness with cyanosis (blue lips or fingertips). A descent of 500–1,000 metres is often enough to begin recovery. Supplemental oxygen and dexamethasone (for HACE) or nifedipine (for HAPE) can buy time if descent is not immediately possible, but neither replaces descent.

Frequently Asked Questions

Does physical fitness protect against altitude sickness?
No. Altitude sickness is determined primarily by how fast you ascend and individual physiological sensitivity, not by cardiovascular fitness. Elite athletes get AMS at the same rates as sedentary travellers at the same altitude and ascent rate.

Can I take altitude sickness medication without a prescription?
Acetazolamide (Diamox) requires a prescription in most countries. Ibuprofen can reduce headache symptoms but does not treat the underlying acclimatisation deficit. Always consult a travel medicine physician.

Is Nairobi high enough to cause altitude sickness?
Nairobi sits at 1,700 metres. This is unlikely to cause AMS in most travellers but may cause mild fatigue on arrival, particularly after a long-haul flight. It is a useful acclimatisation base before travelling to higher altitudes.

Can I fly home immediately after symptoms of altitude sickness?
Descending by air is the fastest form of descent. Flying is appropriate and safe if you are experiencing AMS and need to get to lower altitude quickly. The cabin pressure in commercial aircraft is equivalent to approximately 1,800–2,400 metres, so it may not resolve symptoms at once but will improve your condition relative to staying at altitude.