Causes of pelvic inflammatory disease: Age: The high incidence of pelvic inflammatory disease is between 15 and 25 years of age. The susceptibility of young women to pelvic inflammatory disease may be related to frequent sexual activity, ectopic cervical columnar epithelium, and poor mechanical defense of the cervical mucus. Sexual activity: pelvic inflammatory disease occurs more often in sexually active women, especially those who have sexual intercourse for the first time at a young age, have multiple sexual partners, have sexual intercourse too frequently, and whose sexual partners have sexually transmitted diseases. Infections of the lower genital tract: Infections of the lower genital tract such as Neisseria gonorrhoeae cervicitis, chlamydial cervicitis, and bacterial vaginosis are closely related to the occurrence of pelvic inflammatory disease. Infections after surgical operations in the uterine cavity: such as curettage, tubal lavage, hysterosalpingography, hysteroscopy, etc., due to damage, bleeding and necrosis of the mucosa of the genital tract caused by the surgery, resulting in endogenous binging pathogens upstream infection in the lower genital tract. Poor sexual hygiene: menstrual intercourse, use of unclean menstrual pads, etc., can cause inflammation by invasion of pathogens. In addition, low-income groups do not pay attention to sexual health care, vaginal douche people have a high incidence of pelvic inflammatory disease. Direct spread of inflammation from adjacent organs: e.g. appendicitis, peritonitis, etc. spread to the pelvis, with Escherichia coli as the main pathogen. Re-acute attack of pelvic inflammatory disease: Extensive adhesions in the pelvis due to pelvic inflammatory disease, tubal injury, and decreased defensive capacity of the fallopian tubes can easily cause re-infection and lead to acute attack.