Anorexia nervosa and bulimia nervosa are eating disorders associated with life-threatening multisystemic medical complications. This narrative review aimed to present the medical complications most related to these disorders. In anorexia nervosa, many of them are linked to malnutrition and underweight, usually reversible with renutrition and weight restoration, although refeeding can also be linked to some medical complications. Purging behaviors observed in the anorexia nervosa binge-purging subtype and bulimia nervosa have been mainly related to hydrolectrolyte and acid-base disturbances, in addition to local complications. Thus, an early identification and therapeutic intervention of these disorders is considered crucial. Integral medical monitoring should be ensured to prevent potential serious complications from the early stages, with the involvement of physicians, psychologists, nutritionists, and other specialists in a multidisciplinary approach according to the patient's needs.