What do most people suffer from on mount Everest?

Most people climbing Mount Everest suffer from altitude sickness, which can range from mild symptoms like headaches and nausea to severe conditions such as high-altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE). These conditions arise due to the extreme elevation, where the oxygen levels are significantly lower, leading to reduced oxygen availability for the body. Additionally, climbers often face extreme weather conditions, physical exhaustion, and the risk of frostbite. Proper acclimatization and preparation are crucial to mitigate these risks.