Chemical cystitis is caused by irritation of the bladder mucosa by chemical factors, mostly considered to be caused by chemotherapeutic drugs perfusion in the bladder, patients will have frequent urination, urinary urgency and other symptoms, the symptom will improve after stopping the chemical perfusion, and patients usually need to drink more water. Chemical cystitis is caused by the bladder mucosa is stimulated by chemical irritants, may lead to bladder mucosa congestion, edema, erosion. The patient’s chemical cystitis is mainly caused by bladder cancer patients’ bladder perfusion with chemotherapeutic drugs such as epirubicin and gemcitabine in the bladder, and these chemotherapeutic drugs will cause irritation to the bladder wall or bladder mucous membrane, which induces inflammation of the bladder. If the patient develops chemical cystitis will be manifested as frequent urination, urinary urgency, urinary pain and other manifestations, and some patients may develop hematuria or blood clots in severe cases. Chemical cystitis usually resolves when the chemotherapy is stopped. In addition, patients should drink more water and urinate frequently during the period of bladder perfusion. To summarize, if chemical cystitis occurs, you should consult a doctor in time, and you need to choose the appropriate measures for treatment under the guidance of the doctor.