a spasm, or cramp, caused by a disturbance in the body’s calcium metabolism. Such spasms may be parathyroprival—that is, they may result from insufficiency or complete absence of function of the parathyroid glands (either because of surgical removal or because of an inflammation or other pathological condition)—or may be caused by fluid loss owing to repeated vomiting or diarrhea (also called gastrointestinal tetany).
The principal manifestations of tetany are tonic muscular spasms of varying duration in different parts of the body, increased electromechanical excitability of the motor and sensory nerves, and increased excitability of the autonomic nervous system leading to the malfunction of internal organs. During an attack of tetany, sudden death may occur from asphyxia or heart failure. In latent tetany, an attack may be provoked by some factor such as infection or intoxication. Treatment of tetany is based on replacement therapy—that is, the injection of such substances as parathyroid hormone or calcium preparations.