What causes PID?

The most common cause of PID is a sexually-transmitted infection which has spread from the lower genital tract. Common causative organisms include:

  • Chlamydia trachomatis (14-35% cases)
  • Neisseria gonorrhoeae (2-3% cases)
  • Mycoplasma genitalium

PID can also be caused by normal vaginal flora which migrate to the upper genital tract4.

Often no pathogen is identified.

Learning bite: Pathogen negative PID is common.