Hypomagnesemia is an electrolyte disturbance with low levels of serum magnesium. Normal magnesium levels are between 1.46–2.68 mg/dL (0.6-1.1 mmol/L) with levels less than 1.46 mg/dL (0.6 mmol/L) defining hypomagnesemia. Like with other electrolyte and fluid imbalances (see also: hyponatremia, hypokalemia, hypocalcemia, hypercalcemia),[1] hypomagnesemia can cause neuropsychiatric symptoms including psychosis.

Comparison of Various Electrolyte Disturbances

Hypo (Low Concentration) Hyper (High Concentration)
Sodium Hyponatremia: Nausea, malaise, stupor, coma, seizures Irritability, stupor, coma
Potassium Hypokalemia: Arrhythmias, muscle cramps, spasm, and weakness. ECGs will show U waves and flattened T waves Arrhythmias, muscle weakness. ECGs will show Wide QRS and peaked T waves.
Calcium Hypocalcemia: Tetany, seizures, QT prolongation, twitching (e.g. - Chvostek sign), spasm (e.g. - Trousseau sign) Hypercalcemia: Stones (renal), bones (pain), groans (abdominal pain), thrones (urinary frequency), psychiatric overtones (anxiety, altered mental status)
Magnesium Hypomagnesmia: Tetany, torsades de pointes, hypokalemia, hypocalcemia Decreased deep tendon reflexes, hypotension, lethargy, bradycardia, cardiac arrest, hypocalcemia
Phosphate Bone loss, osteomalacia (adults), rickets (children) Renal stones, metastatic calcifications, hypocalcemia

Hyperparathyroidism Fig. 1