Cystitis does not usually cause thigh pain. Cystitis is an inflammation that occurs mainly on the mucosal surface of the bladder. This causes symptoms such as frequent urination, urinary urgency, painful urination, or a feeling of incomplete urination and pain in the lower abdomen, but does not cause pain in the thighs. If the inflammation develops further, it can cause upstream infection, such as ureteral infection or pyelonephritis, which may cause symptoms such as low back pain or abdominal pain, and may also have an elevated body temperature or bleeding with urination, but no thigh pain. It is recommended that the patient be further examined to determine the cause of the thigh pain and to actively treat the inflammation of the bladder to avoid upper urinary tract infections or elevated body temperature. Patients need to retain clean urine for bacterial culture and drug sensitivity testing, so that the specific pathogenic bacteria of the infection can be clarified, and can be targeted to select sensitive antibiotics for treatment.