Pelvic inflammatory disease (PID) is caused by pathogenic infections, and lower genital tract infections, uterine operations, and poor hygiene are predisposing factors. Pelvic inflammatory disease is caused by pathogen infection, and common pathogens include exogenous pathogens such as Neisseria gonorrhoeae and Chlamydia trachomatis, and endogenous pathogens such as Staphylococcus aureus, Streptococcus haemolyticus, Escherichia coli, and so on. The above pathogens can usually spread upstream along the mucous membranes of the genital tract, through the lymphatic system only, or directly. For some patients with lower genital tract infections such as Neisseria gonorrhoeae cervicitis and bacterial vaginitis, they are prone to complications of pelvic inflammatory disease when their conditions are not properly controlled. Curettage and hysteroscopy may lead to mucosal injury and bleeding in the reproductive tract, increasing the chance of upstream infection by pathogens in the lower reproductive tract. Sexual intercourse during menstruation, sexual intercourse or failure to pay attention to personal hygiene in daily life may induce pelvic inflammatory disease. There are many other causes of pelvic inflammatory disease. It is recommended that those who are diagnosed with pelvic inflammatory disease adjust their mindset and actively cooperate with the doctor for treatment.