The aim of the paper was to investigate health aspects of high altitude trekking such as preparation for the physical exertion during trekking at high altitude, the impact of mountaineering on the daily life before and after the expedition, the effect of high-mountain conditions on health and well-being. It was found that in the pre-departure period trekkers commonly train to ensure that they are physically fit for the expedition. They train alone or under the supervision of a trainer. Self-prepared workouts may turn out to be insufficient due to the lack of appropriate training plans. The most challenging aspects of high altitude trekking for the body include carrying too heavy equipment, dealing with illegibly marked routes, wearing inappropriate clothing, having an unbalanced diet, not having enough water, which can lead to dehydration and infections. Misconduct by other people poses a risk. The specific type of effort involved in mountaineering requires balanced nutrition in terms of both micro- and macro-elements. To find the right combination, one has to either experiment or seek advice from a dietitian. However, relatively few people consult a nutrition coach. Among sanitary problems, the most serious one is inappropriate human waste disposal, the resulting lack of drinkable water. Some of the observed problems result from insufficient regulations regarding the conduct in the mountains and from trekkers’ lack of awareness regarding good practices in such extreme conditions.