Cheminet G, et al. - In this observational monocentric study, between 1st July 2000 and April 2015, the researchers described the epidemiological, clinical, etiological characteristics, and the biological abnormalities of consecutive inpatients with extreme hypomagnesemia. For the purpose of this investigation, all inpatients with extreme hypomagnesemia, defined by at least one plasma magnesium concentration (P_Mg) below 0.3 mmol/L, were involved. The findings from the present study suggested that extreme hypomagnesemia was rare in inpatients, and was frequently linked with severe hypocalcemia. The main contributory causes were digestive disorders and drugs.