Climbing Mount Kilimanjaro (5,895 m / 19,341 ft) is an unforgettable adventure, but the high altitude can be tough on your body.
Altitude sickness affects many climbers, so understanding the risks, symptoms, and prevention strategies is essential for a safe and successful summit.
Use this guide to learn what Kilimanjaro altitude sickness is, how to avoid it, and what to do if symptoms appear during your climb.

What Is Altitude Sickness on Mount Kilimanjaro?

Altitude sickness, also known as Acute Mountain Sickness (AMS), occurs when your body cannot adjust quickly enough to the lower oxygen levels found at higher elevations (usually above 2,500 m).
On Mount Kilimanjaro, mild AMS can escalate into more serious and life-threatening conditions such as High Altitude Pulmonary Edema (HAPE) and High Altitude Cerebral Edema (HACE) if not treated promptly.
Understanding the different altitude zones on Kilimanjaro helps you recognise where the risks increase.

Types of Altitude Sickness on Kilimanjaro

Acute Mountain Sickness (AMS)
The most common form of altitude sickness. Symptoms include headache, nausea, loss of appetite, fatigue, poor sleep and dizziness. Mild AMS can often be managed with rest, hydration and medication, but if symptoms worsen you must descend.

High Altitude Pulmonary Edema (HAPE)
A build-up of fluid in the lungs. Signs include shortness of breath at rest, persistent cough (sometimes with frothy or pink sputum), chest tightness and extreme fatigue. HAPE is life-threatening and requires immediate descent and medical treatment.

High Altitude Cerebral Edema (HACE)
Swelling of the brain caused by fluid. Symptoms include confusion, loss of coordination (ataxia), behaviour changes, severe headache, and in extreme cases hallucinations. HACE is a medical emergency and demands rapid descent.

How to Avoid Altitude Sickness on Kilimanjaro

Use these Kilimanjaro altitude sickness tips to reduce your risk during the climb:

• Choose a longer route: Select 7–9 day itineraries such as Lemosho or the Northern Circuit to allow gradual acclimatization and smaller daily elevation gains.

• Hydrate consistently: Drink around 3–4 litres of water per day. Avoid excessive caffeine and alcohol, which can dehydrate you.

• Walk “pole pole” (slowly): Maintain a relaxed, steady pace to conserve energy and help your body adapt to altitude.

• Eat well: Focus on high-carbohydrate, calorie-dense meals and regular snacks to keep your energy levels up.

• Monitor symptoms: Take any headache, nausea or dizziness seriously. Inform your guide, rest, and descend if symptoms become moderate or severe.

Medications for Kilimanjaro Altitude Sickness

Always consult your doctor before taking any medication for altitude sickness. The following are commonly used on high-altitude treks:

Acetazolamide (Diamox)
Used to prevent and treat mild AMS by helping your body acclimatize faster.
Typical dose: 125–250 mg twice daily, starting one to two days before ascent and continuing while climbing.
Possible side effects: tingling in fingers or toes, increased urination, change in taste.

Dexamethasone
A steroid used for severe AMS or HACE. It reduces brain swelling and is intended for emergency use only, together with immediate descent.
Possible side effects: mood changes, stomach irritation and insomnia when used for longer periods.

Nifedipine
Used to treat HAPE by lowering pressure in the lungs. It should only be used under medical guidance in emergencies.
Possible side effects: dizziness and lowered blood pressure.

Ibuprofen and Pain Relievers
Help relieve headaches and general discomfort related to mild AMS. Use with food to protect the stomach.

Anti-nausea medication (for example, Ondansetron)
Helps control nausea and vomiting so you can keep eating and drinking during your climb.

Training Tips to Reduce the Risk of Altitude Sickness

Good physical preparation improves your comfort and resilience at altitude, even though it does not prevent AMS completely.

• Build cardiovascular fitness: Run, cycle, swim or brisk-walk 3–5 times per week for 3–6 months before your trek.

• Train on hills and stairs: Practice with a 10–15 kg day pack to simulate Kilimanjaro’s uphill sections.

• Include strength work: Squats, lunges, step-ups and core exercises help your legs and back handle long hiking days.

• Get altitude exposure if possible: Spend time hiking at elevations above 2,000 m before your trip, or use altitude facilities where available.

Risk Levels for Kilimanjaro Altitude Sickness

Your personal risk depends on how fast you ascend, your route choice, and any previous history of altitude problems.

Low Risk
You ascend slowly, gain less than 500 m per day above 3,000 m, and have no previous AMS history. Preventive medication is usually not required, though some trekkers still choose Diamox.

Moderate Risk
You gain more than 800–1,000 m in a single day or have had mild AMS before. Longer routes and careful pacing are essential; Diamox prophylaxis may be recommended by your doctor.

High Risk
You have a history of AMS, HAPE or HACE or you plan a short, fast ascent (for example, a 5-day climb). You must choose a longer itinerary, monitor symptoms closely, and descend immediately if serious signs appear.

Other High-Altitude Challenges on Kilimanjaro

Altitude sickness is not the only challenge on Kilimanjaro. Climbers also need to be aware of:

• Dehydration: Caused by dry air, exertion and cold. Aim for clear to pale-yellow urine.

• Hypothermia: Rapid heat loss due to wind, rain and cold temperatures. Use a layering system and stay dry.

• Frostbite: Protect fingers, toes, ears and nose with warm, insulated clothing and gloves.

• Exhaustion: Over-pacing or under-fueling leads to extreme fatigue. Walk slowly and eat regularly.

• Sleep problems: Many climbers sleep poorly at altitude. Good sleeping bags, warm layers and a calm evening routine help.

Frequently Asked Questions About Kilimanjaro Altitude Sickness

What is Kilimanjaro altitude sickness?
It is Acute Mountain Sickness (AMS) brought on by reduced oxygen at high altitudes. Typical symptoms include headache, nausea, loss of appetite, fatigue and dizziness.

How can I avoid altitude sickness on Kilimanjaro?
Choose a longer route, go slowly, drink plenty of water, eat well, and consider Diamox after speaking to your doctor. Always listen to your guide’s instructions.

What are the danger signs of severe altitude sickness?
Shortness of breath at rest, confusion, loss of balance, chest tightness, or worsening headache and vomiting. These signs require immediate descent and medical attention.

Can altitude sickness on Kilimanjaro be fatal?
Deaths are rare but can occur if HAPE or HACE are not treated quickly. Early recognition and rapid descent save lives.

How long should I spend acclimatizing?
Most climbers do best on 7–9 day itineraries, which give the body time to adapt and significantly increase summit success rates.

Plan Your Safe Kilimanjaro Climb

Reaching the summit of Mount Kilimanjaro is an incredible achievement. By understanding altitude sickness and following these Kilimanjaro altitude sickness tips, you give yourself the best chance of a safe, successful and enjoyable climb.
When you are ready to plan, get in touch for expert advice, carefully designed itineraries and experienced mountain guides who prioritize your health and safety from start to finish.