Fractional Excretion of Magnesium

**Semantic type:** Laboratory Procedure

**Definition:** The percentage of the total magnesium filtered by the kidney that is excreted in the urine. The fractional excretion is calculated by multiplying urinary magnesium concentration by the plasma creatinine concentration, then dividing by the urinary creatinine concentration multiplied by the plasma magnesium concentration. The resulting ratio is multiplied by 100.

**Synonyms:** - FEMG - Fractional Magnesium Excretion - Fractional Magnesium Excretion