Hypomagnesaemia masquerading as hypoparathyroidism.

Magnesium deficiency is a common clinical problem. Dietary malabsorption and renal wasting are the commonest causes. Hypomagnesemia induces a state of functional hypoparathyroidism due to decreased secretion of parathormone (PTH) as well as resistance to its action. Contrary to typical autoimmune hypoparathyroidism, it is associated with decreased levels of serum phosphate. We report a patient who presented with hypocalcemic tetany associated with hypomagnesaemia due to renal wasting. Subsequently, he improved with magnesium supplementation of therapy.