Abstract: Hemorrhagic cystitis (HC) is one of the common complications of allogeneic hematopoietic stem cell transplantation, which is the key point of transplantation prevention and treatment. This article introduces the etiology, pathogenesis, prevention and treatment of HC. The occurrence of HC is often related to the toxicity of high-dose radiotherapy and chemotherapy before transplantation, gene polymorphism of drug metabolism enzyme, viral infection, graft-versus-host disease, patient age, sex, donor type and transplantation method. Diagnosis of HC is not difficult, based on the history, typical clinical manifestations, and necessary auxiliary tests. Effective preventive measures are adequate hydration and alkalization of urine, diuresis and the application of Mesna. The treatment mainly includes antiviral therapy, immunotherapy, bladder irrigation, bladder perfusion, hyperbaric oxygen therapy and surgical treatment.

Key words: hemorrhagic cystitis; allogeneic hematopoietic stem cell transplantation; BK virus; child