Soreness and swelling after inserting a catheter may be a normal phenomenon, or it may be caused by secondary infection. 1. Normal phenomenon: inserting a catheter will cause stimulation of the urethra, causing local swelling and soreness, if only a slight feeling of soreness, generally do not need to worry about, is a normal physiological phenomenon. 2. Secondary infection: inserting a catheter is a foreign body, stimulation may cause secondary bacterial infection, causing local inflammatory reaction resulting in swelling and congestion, can also lead to symptoms of soreness. After inserting a catheter, it is recommended to consult a doctor, under the guidance of the doctor for examination, to clarify the cause of the disease, and then follow the doctor’s instructions for treatment.