Altitude sickness is a serious and potentially dangerous risk when climbing Kilimanjaro. It is the most common cause of tourist deaths on Mount Kilimanjaro and needs to be taken seriously.
Beware that young, fit and healthy climbers are as much at risk as anyone else. Even when taking all the recommended and important precautions and implementing all best practice safety measure, altitude sickness can strike suddenly and unexpectedly, so there’s always a risk.