The direct and successful management of primary, primary and mixed acid-base disorders, whether urgent or emergency, engages emergency and intensive medicine and not only. This is a particularly complex but also common, almost daily, medical problem that touches upon many specialties such as pulmonology, nephrology, pathology, emergency medicine and intensive care, cardiology, not only at the level of emergency cases but also at the level of outpatient clinics. The purpose of this publication is to highlight the multifaceted nature of this subject, to analyze it in a clear and simple way, and to lead to a rapid understanding of the basic pathophysiological phenomena and disturbances of acid-base balance.