Mountain sickness: physiological challenges, diagnosis and treatment

INTRODUCTION. The first descriptions of altitude sickness were made in (1540-1600). Nowadays, different cities in the world are at high altitude, for example Qinghai-Tibetan Plateau in China occupies an area of almost 2.5 million inhabitants km2, with an average elevation of over 4,500 m. Altitude sickness should be a major concern for anyone who normally resides at sea level. METHOD. A search for information was carried out in the period August-December 2024 in the SciELO, LILACS, Scopus, PubMed-MedLine databases, the Google Scholar search engine, as well as in the ClinicalKeys services. RESULTS AND DISCUSSION. The partial pressure of arterial oxygen (PaO2 ) decreases with altitude, which produces progressive tissue hypoxia. The normal compensatory response to hypobaric hypoxia is called acclimatization. Its main characteristic is increased ventilation. The ability to acclimatize varies widely among individuals and depends on many factors, including the degree of hypoxic stress (rate of ascent, altitude reached), the intrinsic ability of the individual to compensate for the decrease in PaO2, and extrinsic factors. Progressive ascent produces greater hypoxic stress, requiring greater degrees of physiological and behavioral adaptations to preserve function. The more rapid the ascent and the higher the altitude, the greater the stress. Below 1500 m, symptoms of high altitude illness are generally not manifest. From approximately 1500 to 2500 m, symptoms are generally mild, if experienced at all. From approximately 2500 m, mild to moderate symptoms become quite common among unacclimatized visitors after a rapid ascent. As a general rule, people who normally reside below 1500 m should avoid an abrupt ascent to altitudes above 2800 m for sleeping. Sedative-hypnotics should be avoided during acclimatization. Abstinence from alcohol is safest