If magnesium is low, you may experience a combination of muscle cramps, anxiety, sleep trouble, and irregular heartbeat

https://www.scribd.com/document/1025215847/Understanding-Leg-Cramps-and-Magnesium-A-Guide-for-Readers-158837

If magnesium is low, you may experience a combination of muscle cramps, anxiety, sleep trouble, and irregular heartbeat, indicating a need for evaluation.