Introduction: Any individual at elevation above 2500m may develop one or more forms of acute altitude sickness. These include nonspecific symptoms or acute mountain sickness which can progress to high altitude cerebral edema or high altitude pulmonary edema. Purpose: The aim of this diploma thesis is to introduce main health risks that arise with high altitude and to present first aid procedures, related to exposure to high altitude. The goal of this work is to present and explain mechanisms of onset of altitude sickness, what are the most common forms of altitude sickness, how to prevent the onset of altitude sickness, what are the signs and symptoms that indicate the development of altitude sickness and what are the correct first aid procedures. Methods: A systematic and thorough review of scientific literature, published in English or Slovene language was performed. We included scientific papers, published in the period between 2002 and 2019, found on bibliographic databases (e.g. Cinahl, Science direct, Pubmed), COBISS and Google Scholar. Results: Each individual can prevent occurrence of altitude sickness with taking care for proper acclimatization process. But if complications occur, the proficiency first aid is an important skill. However, the best measure to prevent occurrence of altitude sickness is. First aid for altitude sickness is based on the early recognition of signs and symptoms. When first symptom occur, it is necessary to stop further ascent. If the symptoms do not improve despite the measures and treatment, it is crucial to immediately descend to lower altitude. Some additional measures also include supplemental oxygen, the use of a hyperbaric chamber and treatment with medications. Discussion and conclusion: Since the incidence of altitude sickness is increasing, the importance of prevention and first aid is gaining extreme importance in ensuring the health of the population. Healthcare professionals may be involved in expeditions as members of the emergency medical team in the field or as members of a health team in the emergency response department. The role of health professionals is to properly inform people about prevention of altitude sickness, to help identify signs and symptoms and to provide first aid in the event of altitude sickness. However, additional formal education of health professionals in this field is required to ensure quality implementation of healthcare interventions.