Lithium is a medication commonly used to treat bipolar disorder and other psychiatric conditions. However, long-term use of lithium can lead to parathyroid dysfunction, known as lithium-induced parathyroid disease. The exact mechanism underlying lithium-induced parathyroid disease is not fully understood. Still, it is believed that lithium interferes with the normal function of the parathyroid gland by inhibiting the synthesis and secretion of parathyroid hormone (PTH) and impairing the sensitivity of the parathyroid gland to calcium. The management of lithium-induced parathyroid disease depends on the type and severity of parathyroid dysfunction. In patients with hypoparathyroidism, treatment involves the replacement of calcium and vitamin D supplements. In severe cases, intravenous calcium may be necessary. In patients with hyperparathyroidism, treatment consists in discontinuing lithium therapy and monitoring serum calcium and PTH levels. In situations where hyperparathyroidism persists, or complications like kidney stones or osteoporosis arise, surgery may become necessary.