Why get tested? To evaluate the level of magnesium in your blood and to help determine the cause of abnormal calcium and/or potassium levels
When to get tested? If you have symptoms (such as weakness, irritability, cardiac arrhythmia, nausea, and/or diarrhoea) that may be due to too much or too little magnesium or if you have abnormal calcium or potassium levels
Sample required? A blood sample drawn from a vein in your arm