Adequate fluid resuscitation requires a deep understanding of the physiology of liquids, the mechanisms of regulation of the endothelium and the composition of each type of intravenous solution used. This work addresses the key points of the development of solutions throughout history, contrasts the physiological and pathological canons of hemodynamic and endothelial regulation of fluids, and concludes by describing the composition of various solutions, groups, beneficial and adverse effects, all on the basis of the most recent evidence from international literature.