Abnormal antidiuretic hormone secretion syndrome refers to a functional impairment of water excretion in the body due to the continuous secretion of endogenous antidiuretic hormone in the body. If the patient has excessive water intake, he or she may experience weakness and even confusion, coma, drowsiness and convulsions. If a patient experiences any of these symptoms, it is important to treat the patient promptly to avoid life-threatening conditions. The common cause is lung oat cell carcinoma, but clinically, pancreatic cancer, lymphosarcoma, duodenal cancer, thymoma, infection in the lung and bleeding, lesions of the central nervous system including inflammation, bleeding and tumor can also cause patients to develop abnormal antidiuretic hormone secretion syndrome. Moreover, the clinical use of some drugs may also induce the abnormal antidiuretic hormone secretion syndrome, such as carbamazepine, vincristine, clofibrate, tricyclic antidepressants, etc., which can make the abnormal antidiuretic hormone secretion syndrome appear.