Approach to the patient with hypomagnesaemia

The kidneys play a central role in the maintenance of a normal magnesium balance. The distal renal tubule, especially the thick ascending limb of the loop of Henle, and the distal convoluted tubule mediate the regulation of a normal magnesium balance. The clinical assessment of magnesium deficiency is described. Genetic causes are described in detail. Acquired causes are more common and often related to drug therapy or toxicity, or to metabolic acidosis or phosphate depletion.