[Abnormalities in serum magnesium concentration].

Magnesium (Mg) therapy is often proposed against stress and to correct asthenia. Thus our aim has been to review the role of Mg, the mechanisms of its homeostasis before detailing the clinical presentations and etiologies of hypo- and hypermagnesemia and their exploration. Hypomagnesemia frequently occurs but is clinically rarely recognized without biological serum ionic determinations because causing atypical signs miming those of other ion deficiencies. Hypermagnesemia is uncommon but often occurs in the presence of renal insufficiency especially with excess of Mg administration.