[Lithium-induced hyperparathyroidism]

Lithium is a medication successfully being used for the treatment of bipolar disorder. Lithium-induced hyperparathyroidism (LIH) is a little known complication that may arise due to the use of lithium. Symptoms of LIH are often similar to the underlying psychiatric illness for which lithium was indicated. It is thus difficult to differentiate between these, resulting in significant 'doctors' delay' in the diagnosis of LIH. The authors present three cases in this article. In the first case concerning a 51-year-old woman, they illustrate that LIH and subsequent hypercalcaemia are often diagnosed by coincidence. In the second case concerning a 47-year-old woman, they show that it can be quite complicated to locate the underlying aberration of the parathyroid and that medication may be an eligible alternative to surgery. In the third case, a 56-year-old woman, they show the need for cogency regarding appropriate surgical strategy as recurrences are quite common.