What Causes Pelvic Inflammatory Disease (PID)?

Pelvic inflammatory disease (PID) refers to inflammation of the female reproductive organs, the connective tissues surrounding the uterus, and the pelvic peritoneum. If PID is not promptly treated and managed, increased inflammatory exudation may lead to adhesions in local tissues, thereby exacerbating lower abdominal pain. As adhesions progress further, “frozen pelvis” may develop. So, what causes pelvic inflammatory disease? Below is an overview.

Causes of Pelvic Inflammatory Disease

1. Poor Hygiene During Menstruation

Neglecting hygiene during menstruation predisposes women to PID. Examples include infrequent changing of sanitary products, inadequate cleaning of the external genitalia, and engaging in sexual intercourse during menstruation. During menstruation, the endometrium sheds and is expelled as menstrual blood, which often contains large numbers of pathogenic bacteria. Poor menstrual hygiene thus increases the risk of pelvic infection.

2. Inflammation of Adjacent Organs

Inflammation in adjacent organs—such as appendicitis or peritonitis—can spread directly to the female internal genital organs due to their anatomical proximity, thereby triggering PID. Chronic cervicitis may also lead to pelvic connective tissue inflammation via lymphatic dissemination.

3. Post-Gynecological Surgical Infection

Postoperative infection following gynecological procedures is one of the most common causes of PID. After surgery, women’s bodies are relatively weakened and immune resistance diminished, rendering them more susceptible to invasion and infection by bacteria and other pathogens—potentially triggering PID. Common procedures associated with postoperative infection include induced abortion, insertion or removal of intrauterine devices (IUDs), tubal irrigation, and endometrial polypectomy.

4. Frequent Sexual Intercourse

Frequent sexual intercourse may contribute to PID development. Vigorous intercourse can cause trauma or friction-induced injury to the vaginal mucosa, facilitating bacterial invasion and subsequent pelvic infection. Common causative pathogens include Staphylococcus aureus, Escherichia coli, and anaerobic bacteria. Additionally, use of intrauterine contraceptive devices (IUDs) may also increase the risk of PID.

The above outlines the major causes of pelvic inflammatory disease: poor menstrual hygiene, inflammation of adjacent organs, post-gynecological surgical infection, and frequent sexual intercourse. We hope this information is helpful to you.