The first is non-gonococcal urethritis, which is mainly caused by unclean sexual contact resulting in mycoplasma and chlamydia infection. The patient will generally have a history of unclean sexual contact, itchy or burning urethra, or appear to have frequent urination, urinary urgency, etc., need to carry out mycoplasma, chlamydia test to further confirm the diagnosis. Second, gonococcal infection is caused by the infection called gonorrhea, which can cause itching in the urine. At the same time, accompanied by frequent urination, urinary urgency, accompanied by increased yellow discharge in the urethra, the majority of cases are also through unclean sexual contact infection, need to conduct gonococcal culture test to confirm the diagnosis. Third, non-specific urethritis, such as poor external hygiene of the urethra or male circumcision, circumcision, etc., which can cause the urethra to be infected with common pathogens such as Escherichia coli, Klebsiella, or Pseudomonas aeruginosa, resulting in itchy urine, requires a urine culture test to confirm the diagnosis.