Diagnosis and treatment of hyperparathyroid crisis：a report of 4 cases BAI Yan-xia*, MA Qing-yong, YAN Li-ying, et al . *Department of Otorhinolaryngology Head and Neck Surgery, the First Affiliated Hospital, Medical College of Xi’an Jiaotong University，Xi’an 710061，China Corresponding Author： MA Qing-yong, E-mail: qyma56@xjtu.edu.cn Abstract Objective To explore the diagnostic and therapeutic method of hyperparathyroid crisis. Methods The clinical data, the operative technique, the therapeutic effect of 4 cases which were treated in First Affiliated Hospital of Xi’an Jiaotong University from January 2005 to May 2007 were presented. Through reviewing pertinent literature, we discuss the qualitative diagnosis、level diagnosis and operative juncture of primary hyperparathyroidism complicating hyperparathyroid crisis. Results The three patients were healed by promptly exploratory parathyroidectomy and medical treatment. One patient died for complicating of multiple organ dysfunction. Conclusions Promptly exploratory parathyroidectomy after temporal medical treatment is an effective method to rescue the patient of primary hyperparathyroidism complicating hyperparathyroid crisis；The exploratory parathyroidectomy can be successed on preoperative definite diagnosis and accurate localization、frozen section and quickly PTH determination in the operation.