An endocrine disorder most commonly caused by removal or damage to the parathyroid glands during thyroidectomy. Damage to these glands may also result from accident or disease. The physical consequence is a lowering of the calcium level of the blood, leading to cramps, spasms, and tetany. These effects are usually accompanied by psychological symptoms, and for this reason the disorder is classified by the American Psychiatric Association as an acute brain syndrome associated with metabolic disturbance. The most common psychological symptoms are depression, memory defect, and emotional lability—that is, unstable and shifting moods. Both the physical and mental symptoms can be relieved by the medical administration of calcium salts and vitamin D