Other diagnostic studies can include evaluation for the underlying cause of hypomagnesemia. This requires a thorough investigation for the presence of diabetes mellitus, alcoholism, gastrointestinal conditions involving poor absorption and/or poor nutritional intake, or a family history of hypomagnesemia without or without other electrolyte abnormalities, and a complete list of medications used. The suspected underlying etiology may be confirmed with urinary studies based on its mechanism via renal wasting or extrarenal cause. Patients with hypomagnesemia due to renal Mg2+ wasting have been suggested to present with a fractional excretion of Mg2+ greater than 4%, whereas those with extrarenal causes present with a much lower percentage, typically 2% or less.

Other diagnostic studies can include evaluation for the underlying cause of hypomagnesemia. This requires a thorough investigation for the presence of:^[1]

• Diabetes mellitus

• Alcoholism

• Gastrointestinal conditions involving poor absorption and/or poor nutritional intake

• Family history of hypomagnesemia

• A complete list of medications used.

The suspected underlying etiology may be confirmed with urinary studies based on its mechanism via renal wasting or extrarenal cause. Patients with hypomagnesemia due to renal Mg2+ wasting present with a fractional excretion of Mg2+ greater than 4%, whereas those with extrarenal causes present with a much lower percentage, typically 2% or less.