Pelvic Inflammatory Disease - Cause
PID, sexually transmitted infection (STI), and bacterial vaginosis
Pelvic inflammatory disease (PID) is usually caused by a sexually transmitted infection (STI) that infects the cervix, which connects the upper vagina to the uterus. When the cervix is infected with an STI, it becomes easier for other bacteria present in the vagina to get into and infect the uterus and fallopian tubes. PID can also develop as a result of bacterial vaginosis (BV), which is a drop in the vagina's "good" organisms and an increase in its potentially "bad" organisms. When this happens and the problem organisms spread into the uterus and fallopian tubes, PID can result. (BV is not sexually transmitted.) See a picture of the female pelvic organs .
The most common causes of PID are:
PID caused by chlamydia may have milder symptoms or no symptoms (compared with PID caused by gonorrhea), which can delay diagnosis.
Practicing safe sex by using condoms prevents STIs. This greatly lowers PID risk. For more information, see the Prevention section of this topic.
For more information, see the topics Gonorrhea, Chlamydia, and Bacterial Vaginosis.
PID and intrauterine devices (IUDs)
Women who have an intrauterine device (IUD) inserted for birth control have a higher risk of getting PID in the first month after insertion, especially if bacterial vaginosis or an STI is present at the cervix at the time of insertion. The insertion procedure may transfer bacteria from the vagina or cervix to the uterus. Your risk of infection can be reduced if:
- You are tested and treated for STIs and bacterial vaginosis (if detected) before IUD insertion.
- The insertion is done carefully to minimize the chance of infection (clean technique).
PID that spreads to abdominal organs
PID can spread to other abdominal organs, either from the pelvic organs through the lymphatic system or from the far ends of the fallopian tubes. This may be more common in women who have just:
- Given birth.
- Had uterine tests or other procedures, such as:
- Had an abortion.