Symptoms of hypomagnesemia
What are the signs, symptoms, and consequences of hypomagnesemia?
Since hypomagnesemia causes hypokalemia and hypocalcemia, all three electrolyte abnormalities commonly occur simultaneously. Because of this it is difficult to know if specific manifestations of hypomagnesemia are due strictly to the magnesium deficiency or to low calcium, potassium, or a mixture. Given that warning, here are the commonly reported manifestations of hypomagnesemia.
Neurologic manifestations are primarily hyperexcitability, which can present as muscle spasms, cramps, Trousseau and Chvostek signs, and tremors. Other symptoms include weakness, apathy, delirium, convulsions, and coma.
Cardiovascular manifestations begin with widened QRS and peaked T-waves, and then progress to prolonged PR interval, further widening of the QRS, and loss of the T-waves with worsening hypomagnesemia. Atrial and ventricular arrhythmias including torsades de pointes are possible.
In retrospective analysis, low magnesium has been associated with increased mortality in multiple clinical scenarios, including ICU, general medicine wards, and in dialysis patients. Though this signal is seen even with controlling for severity of illness, prospective studies have not been done to show a decrease in mortality with replacing magnesium.