ABSTRACT: Intra-abdominal hypertension/abdominal compartment syndrome (IAH/ACS) is a well-recognized entity among surgical subspecialties. Nevertheless, it has been proven to be present in the medical critically ill population. Prospective and retrospective observational studies have found medical patients with IAH/ACS to be associated with death in the intensive care unit and other poor outcomes. Frequently, it is underdiagnosed and undertreated in this patient group. Limitations encountered in these observational studies are their small population size and single-center design. In addition, most studies target consecutive intensive care unit admissions instead of limiting IAH/ACS screening to a predefined population confined by their risk factors (unspecified ascites, mechanical ventilation, positive fluid balance, etc.). Generally, medical patients with IAH/ACS are more severely ill compared with surgical patients. Furthermore, they are less likely to receive treatment targeted at lowering intra-abdominal pressure. Medical treatment of IAH/ACS has not been demonstrated to be specifically effective to avoid decompressive surgery. Identifying medical patients at risk of IAH represents an underresearched area for which training in measurement of abdominal pressure surrogates, awareness of its prevalence, and prevention and treatment of such condition could further improve outcomes in critically ill medical patients.