The Laboratory and Clinical Perspectives of Magnesium Imbalance

Magnesium (Mg²⁺) is a predominantly intracellular cation that plays significant roles in various enzymatic, membrane, and structural body functions. As a calcium (Ca²⁺) antagonist, it is imperative for numerous neuromuscular activities. The imbalance of body Mg²⁺ concentration leads to clinical manifestations ranging from asymptomatic to severe life-threatening complications. Therefore, the contribution of Mg²⁺ measurement regarding various laboratory and clinical aspects cannot be ignored. Mg²⁺ is often described as the forgotten analyte. However, its close relationship with body potassium (K⁺), Ca^2+, and phosphate homeostasis proves that Mg²⁺ imbalance could co-exist as the root cause or the consequence of other electrolyte disorders. Meanwhile, several preanalytical, analytical, and postanalytical aspects could influence Mg²⁺ measurement. This review highlights Mg²⁺ measurement's laboratory and clinical issues and some analyte disturbances associated with its imbalance. Understanding this basis could aid clinicians and laboratory professionals in Mg²⁺ result interpretation and patient management.