Kilimanjaro Altitude Sickness: What You Need to Know

​Climbing Mount Kilimanjaro is an incredible achievement, but one of the biggest challenges trekkers face is altitude sickness. At 5,895 meters (19,341 feet), the air at the summit contains only about 50% of the oxygen available at sea level. This rapid ascent in just a few days makes altitude sickness a serious concern.

What is Altitude Sickness?

Altitude sickness, or Acute Mountain Sickness (AMS), occurs when the body struggles to adapt to lower oxygen levels at high elevations. It can affect anyone, regardless of age, fitness level, or previous climbing experience.

Symptoms of Altitude Sickness

Mild to severe symptoms can appear as early as 2,500 meters (8,200 feet) and may worsen with continued ascent:

• Mild AMS: Headache, dizziness, nausea, fatigue, loss of appetite, and difficulty sleeping.
• Moderate AMS: Severe headaches, persistent nausea, vomiting, and shortness of breath.
• Severe AMS: Life-threatening conditions like HAPE (High Altitude Pulmonary Edema)—fluid buildup in the lungs—or HACE (High Altitude Cerebral Edema)—swelling in the brain. Both require immediate descent to lower altitudes.

Why is Altitude Sickness Common on Kilimanjaro?

Unlike other high-altitude climbs where acclimatisation takes weeks, Kilimanjaro is often climbed in 5-7 days. This fast ascent doesn’t give the body enough time to adjust, making altitude sickness one of the biggest reasons climbers fail to reach the summit.

How to Prevent Altitude Sickness on Kilimanjaro

1. Choose the Right Route

Longer routes, like Machame, allow for gradual acclimatisation and a higher success rate. Avoid shorter, rapid ascents like the Umbwe 4-day trek.

2. Go “Pole Pole” (Slowly, Slowly)

Trekking at a slow, steady pace helps the body adjust. Rushing increases the risk of AMS.

3. Stay Hydrated

Drink 3-5 liters of water per day to aid oxygen flow and reduce symptoms. Dehydration is also a leading cause of failure on Kilimanjaro and often completes with Altitude Sickness for the top spot.

4. Eat Well

Even if you lose your appetite, eating enough calories fuels your body to fight altitude effects.

5. Listen to Your Body

If symptoms worsen, descend immediately. Ignoring severe AMS can be fatal.

Final Thoughts

Altitude sickness is the biggest challenge on Kilimanjaro, but with the right precautions, it can be managed. Choosing a longer route, climbing slowly, staying hydrated, and knowing when to descend will increase your chances of standing on the Roof of Africa safely.