The paper presents a model of diagnostic and therapeutic management of tetany, with special attention paid the role of magnesium and to psychotherapy or psychiatric treatment. Two types of tetany are distinguished: manifest and latent (spasmophilia). The former, due to hypocalcemia, is relatively rare and usually postoperative (parathyroid tetany), while the mechanism of the much more common latent tetany or spasmophilia involves hyperventilation and magnesium deficiency. Latent tetany affects particularly young women. There are many signs of spasmophilia, but none is specific, so this pathology is difficult to diagnose.