There are two causes of itchy urethra after ejaculation, gonadal inflammation and urethral inflammation, as follows: 1. Inflammation of the gonads, such as seminal vesiculitis, epididymitis, prostatitis, when semen flows through the urethra will cause itching and pain in the urethral epithelium. 2. Inflammation of the urethra itself, when semen impinges on the urethra with pressure will cause itching and pain. You can generally identify this by prostate fluid routine, urine routine, and if necessary, urological ultrasound. If the results of the examination reveal high white blood cells, oral levofloxacin can be taken. The patient must also prohibit sexual intercourse for a period of time, as well as quit smoking, alcohol, spicy and stimulating foods, and drink more hot water to reduce the symptoms of the urethra. Chinese medicine identifies this as damp-heat injection, and the patient will also have yellow and red urine, irritability, thirst, and emotional irritability, so you can apply the method of clearing heat and relieving dampness, and you can choose Gentian Diarrhea Liver Soup for treatment.