How common is hypermagnesemia
What is the definition and prevalence of hypermagnesemia?
Hypermagnesemia occurs when serum magnesium rises over 2.1 mg/dL (1.75 mEq/L or 0.86 mmol/L). Hypermagnesemia is less common than hypomagnesemia. Nearly all hypermagnesemia goes undiagnosed. In a study of magnesium levels in 1179 consecutive blood samples sent for electrolytes among hospitalized patients, 59 (5.7%) had a magnesium level over 2.4 mg/dL (0.99 mmol/L), but a magnesium was requested in only 7 of those 59. Studies of outpatients in the community have shown rates from 3% to 10%, depending on the population and magnesium level used to define hypermagnesemia.
Hypermagnesemia is more common in patients with ESRD. In a screening of 101 asymptomatic dialysis patients, ingestion of as little as 281 mg of magnesium resulted in hypermagnesemia.
Though biochemical hypermagnesemia is rare, it is generally well tolerated, and symptomatic hypermagnesemia is quite unusual.