The possible causes of ulcers inside the urethra: First, when suffering from urethritis, there can be mucosal erosion accompanied by ulcers, in the appearance of the mucosa can be seen in the urethra incomplete, accompanied by local oozing blood or oozing yellow ooze, etc., accompanied by local pain or increased pain when urinating, but also accompanied by frequent urination, urinary urgency, small abdominal distension and pain. It is necessary to carry out local anti-infection treatment, and carry out urine routine, urine culture and other tests. Second, sexually transmitted diseases, such as gonorrhea or urethral infection with mycoplasma and chlamydia, can also appear ulcerative changes inside the urethra. This is accompanied by an increase in local discharge, which can be yellow or cellular white discharge from the urethra, and can be accompanied by symptoms such as urinary frequency, urinary urgency, and painful urination, mostly related to sexual contact, and requires testing for gonococcus, mycoplasma, chlamydia, and other related pathogens to confirm the diagnosis. Third, medical operations, such as catheterization, urethral dilation or urethroscopy, can cause local damage to the mucosa of the urethra, resulting in ulcers in the urethra. Mostly related to the medical source of the operation, if there are patients who have had the relevant operation, and the corresponding ulcer changes, then consider the urethritis and urethral mucosa damage caused after the operation.