Physiology and Pathophysiology of Potassium Homeostasis: Core Curriculum 2019

Total-body potassium (K⁺) content and appropriate distribution of K⁺ across the cell membrane is vitally important for normal cellular function. Total-body K⁺ content is determined by changes in excretion of K⁺ by the kidneys in response to intake levels. Under normal conditions, insulin and β-adrenergic tone also make important contributions in maintaining internal distribution of K⁺. However, despite these homeostatic pathways, disorders of altered K⁺ homeostasis are common. Appreciating the pathophysiology and regulatory influences that determine the internal distribution and external balance of K⁺ is critical in designing effective treatments to restore K⁺ homeostasis. We provide an up-to-date review of the regulatory aspects of normal K⁺ physiology as a preface to highlighting common disorders in K⁺ homeostasis and their treatment. This review of K⁺ homeostasis is designed as a resource for clinicians and a tool for educators who are teaching trainees to understand the pivotal factors involved in K⁺ balance.