Urinary tract infection after coitus may be caused by physiological factors or the presence of certain infectious diseases, such as Escherichia coli infection, trichomonas vaginitis, gonococcal disease, etc., which should be promptly consulted to identify the cause. 1. Physiological factors: Urinary tract infection after coitus is likely to occur in women. Due to the physiological structure of women, women’s urethra is relatively short, the urethral opening is close to the vaginal opening, coupled with poor hygiene habits after coitus, which may lead to pathogens into the body, so it is easy to get infected. It is recommended to develop a good cleaning habits, before and after coitus timely cleaning hygiene. 2. Pathological factors: (1) E. coli infection: infection caused by, mainly or E. coli for more. (2) Trichomonas vaginitis: Trichomonas vaginitis is mainly transmitted directly through sexual behavior, but also indirectly through swimming pools, sitting toilets, bath towels and so on. Men infected with trichomonas can have no obvious symptoms, but they can easily become the source of infection, sometimes combined with urinary tract infection, and can also be accompanied by symptoms such as painful sexual intercourse, vulvar itching, and increased vaginal discharge. (3) Gonococcal disease: This is a sexually transmitted disease, which can lead to the spread of pathogens through sexual contact, inducing urinary tract infections, such as adult males infected with gonococcal disease can be manifested as burning, itching, redness and swelling of the urethral orifice, painful urination, urination difficulties and other symptoms of urethral irritation. Urinary tract infection after coitus, should be timely consultation, identify the cause of the disease, by the doctor for targeted treatment. During the treatment period, should temporarily stop sex, change hygiene habits, such as certain infectious diseases caused by urinary tract infection, also need to actively treat the primary disease.