There are many reasons for frequent urination and incomplete urination after chemotherapy, such as chemotherapy side effects, urinary tract infection and others. 1. chemotherapy side effects: chemotherapy itself has certain side effects, everyone’s reaction after chemotherapy is different, some patients will cause urinary symptoms, such as frequent urination, dysuria, painful urination and so on. 2. Urinary tract infections: after chemotherapy due to the patient’s personal immunity decline, so it may induce urinary tract infections, and thus the phenomenon of frequent urination and incomplete urination after chemotherapy, which can be diagnosed by routine urinalysis. 3. Other: in order to protect the liver and kidneys during chemotherapy, some drugs need a lot of hydration to reduce the toxicity of chemotherapy drugs, such as cisplatin. Therefore, the infusion of large amounts of liquid during chemotherapy can also lead to frequent urination. There are many reasons for frequent urination after chemotherapy, if the symptoms are more obvious, it is recommended that patients go to the hospital in a timely manner, in accordance with the doctor’s instructions to take standardized treatment, not to ignore the symptoms, so as not to lead to adverse consequences.