Pelvic inflammatory disease (PID) is an infection of the female reproductive organs. It usually occurs when sexually transmitted bacteria spread from your vagina to your uterus and upper genital tract.

What is it?

Pelvic inflammatory disease (PID) is an infection of the female reproductive organs. It usually occurs when sexually transmitted bacteria spread from your vagina to your uterus and upper genital tract.

Many women who develop pelvic inflammatory disease either experience no signs or symptoms or don't seek treatment. Pelvic inflammatory disease may be detected only later when you have trouble getting pregnant or if you develop chronic pelvic pain.

Pelvic inflammatory disease is important to avoid because it can result in infertility or ectopic pregnancy. Prompt treatment of a sexually transmitted disease can help prevent PID.


Signs and symptoms of pelvic inflammatory disease may include:

  • Pain in your lower abdomen and pelvis
  • Heavy vaginal discharge with an unpleasant odor
  • Irregular menstrual bleeding
  • Pain during intercourse
  • Low back pain
  • Fever, fatigue, diarrhoea or vomiting
  • Painful or difficult urination

PID may cause only minor signs and symptoms or none at all. Asymptomatic PID is especially common when the infection is due to chlamydia. The lack of signs and symptoms increases the likelihood that you'll pass chlamydia to other sexual partners and experience serious damage to your reproductive organs.


Unsafe sexual practices that increase your likelihood of acquiring a sexually transmitted disease (STD) — such as unprotected sex with one or more partners — increase your risk of pelvic inflammatory disease.

Some forms of contraception may affect your risk of developing pelvic inflammatory disease. A contraceptive intrauterine device (IUD) may increase your risk of PID, but a barrier method, such as a condom, reduces your risk. Use of the birth control pill alone offers no protection against acquiring STDs. But the pill may offer some protection against the development of PID by causing your body to create thicker cervical mucus, making it more difficult for bacteria to reach your upper genital tract.

Bacteria may also enter your reproductive tract as a result of an IUD insertion, childbirth, miscarriage, abortion or endometrial biopsy — a procedure to remove a small piece of tissue from your uterine lining for laboratory analysis.

Risk factors

A number of factors may increase your risk of pelvic inflammatory disease, including:

  • Being a sexually active woman younger than 25 years old
  • Having multiple sexual partners
  • Using nonbarrier contraceptives — consistent use of barrier methods protects against PID, but may not protect against other STDs, such as human papillomavirus (HPV) and herpes simplex virus (HSV)
  • Having had an IUD inserted recently
  • Douching regularly, which upsets the balance of good versus harmful bacteria in the vagina and may mask symptoms that might otherwise cause you to seek early treatment
  • Having a history of pelvic inflammatory disease or any sexually transmitted disease


Untreated pelvic inflammatory disease may cause scar tissue and collections of infected fluid (abscesses) to develop in your fallopian tubes and damage your reproductive organs. Complications may include:

  • Ectopic pregnancy. PID is a major cause of tubal (ectopic) pregnancy. In an ectopic pregnancy, the fertilized egg can't make its way through the fallopian tube to implant in the uterus. Ectopic pregnancies can cause massive, life-threatening bleeding and require emergency surgery.
  • Infertility. PID may damage your reproductive organs and cause infertility — the inability to become pregnant after one year of unprotected sex. The more times you've had PID, the greater your risk of infertility. Delaying treatment for PID also dramatically increases your risk of infertility.
  • Chronic pelvic pain. Many women with symptomatic pelvic inflammatory disease develop chronic pelvic pain that may last for months or years. Scarring in your fallopian tubes and other pelvic organs can cause pain during intercourse, exercise and ovulation.


Doctors diagnose pelvic inflammatory disease based on signs and symptoms, a pelvic exam, an analysis of vaginal discharge and cervical cultures, or urine tests.

During the pelvic exam, your doctor uses a cotton swab to take samples from your vagina and cervix. The samples are sent to a laboratory for analysis to determine the organism that's causing the infection.

To confirm the diagnosis or to determine how widespread the infection is, your doctor may recommend other tests, such as:

  • Pelvic ultrasound. This test uses sound waves to create images of your reproductive organs.
  • Endometrial biopsy. During this procedure, a small piece of your uterine lining (endometrium) is removed and tested.
  • Laparoscopy. During this procedure, your doctor inserts a thin, lighted instrument through a small incision in your abdomen to view your pelvic organs.