Also known as: Magnesium; Mag
Formal name: Magnesium
Related tests: Calcium, Potassium, Phosphorus, Parathyroid hormone (PTH), Vitamin D
To evaluate the level of magnesium in your blood and to help determine the cause of abnormal calcium and/or potassium levels
When you have symptoms such as weakness, irritability, cardiac arrhythmia, nausea, and/or diarrhea that may be due to too much or too little magnesium; when you have abnormal calcium or potassium levels
A blood sample drawn from a vein in your arm
Overnight fasting may be required; follow any instructions that you are given.