Hypomagnesemia can be confirm diagnosed by laboratory examination as follow:
1. Determination of serum magnesium: Serum magnesium <0.75mmol / L at diagnosis of hypomagnesemia can be, but it can not reflect the body as a reliable indicator of a lack of magnesium. In addition, magnesium is also affected by blood pH, protein and a variety of factors.
2. Determination of urinary magnesium: such as; @ bed is estimated that there is magnesium deficiency, and normal serum magnesium, urinary magnesium should be determined to do .24 h urinary excretion of magnesium is lower than 1.5mmol, can be diagnosed with magnesium deficiency.
3. Determination of magnesium in blood cells: red blood cells can be measured in the magnesium and muscle magnesium. Which reflect more accurately than were the changes in the body of magnesium, but the complexity of inspection methods.
4. Intravenous magnesium load test: at 12 h with the infusion of 500 ml grape sugar solution containing 30 mmol of magnesium sulfate to collect 24h urine, urinary excretion of magnesium. If imported magnesium> 50% retained in the body to magnesium deficiency, <30% retention of magnesium deficiency can be ruled out. the application of this test should not have renal insufficiency, cardiac mass D obstacles or derivative of the patients with respiratory dysfunction.
5. ECG: patients with hypomagnesemia to show the PR and Q-T interval prolongation of the QRS wave widened, watching segment depression, T wave widened, Low or inverted, U-wave occasional. With hypokalemia similar performance.