which electrolyte is missing if there is tetany
Hypocalcemia is not a term for tetany but is rather a cause of tetany. Causes. The usual cause of tetany is lack of calcium. An excess of phosphate (high phosphate-to-calcium ratio) can also trigger the spasms. Underfunction of the parathyroid gland can lead to tetany. Low levels of carbon dioxide cause tetany by altering the albumin binding of calcium such that the ionized (physiologically influencing) fraction of calcium is reduced; one common reason for low carbon dioxide levels is hyperventilation. Low levels of magnesium can lead to tetany.