What is PID (Pelvic Inflammatory Disease)?

Pelvic inflammatory disease, commonly called PID, is an infection of the female reproductive organs. PID is one of the most serious complications of a sexually transmitted disease in women: It can lead to irreversible damage to the uterus, ovaries, fallopian tubes, or other parts of the female reproductive system, and is the primary preventable cause of infertility in women.

Each year, more than 1 million women in the U.S. experience an episode of PID. As a result of PID, more than 100,000 women become infertile each year. In addition, a large proportion of the 100,000 ectopic (tubal) pregnancies that occur each year can be linked to PID. The rate of infection is highest among teenagers.
What causes PID?

PID occurs when bacteria move upward from a woman's vagina or cervix (opening to the uterus) into her reproductive organs. Many different organisms can cause PID, but many cases are associated with gonorrhea and chlamydia, two very common bacterial STDs. A prior episode of PID increases the risk of another episode because the reproductive organs may be damaged during the initial bout of infection.

Sexually active women in their childbearing years are most at risk, and those under age 25 are more likely to develop PID than those older than 25. This is partly because the cervix of teenage girls and young women is not fully matured, increasing their susceptibility to the STDs that are linked to PID.

The more sex partners a woman has, the greater her risk of developing PID. Also, a woman whose partner has more than one sex partner is at greater risk of developing PID, because of the potential for more exposure to infectious agents.

Women who douche may have a higher risk of developing PID compared with women who do not douche. Research has shown that douching changes the vaginal flora (organisms that live in the vagina) in harmful ways, and can force bacteria into the upper reproductive organs from the vagina.

Women who have an intrauterine device (IUD) inserted may have a slightly increased risk of PID near the time of insertion compared with women using other contraceptives or no contraceptive at all. However, this risk is greatly reduced if a woman is tested and, if necessary, treated for STDs before an IUD is inserted.

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
- Being in a sexual relationship with a person who has more than one sex partner
- Having unprotected sex
- 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 infection
What are PID symptoms?

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, diarrhea 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.
How is PID diagnosed?

PID is difficult to diagnose because the symptoms are often subtle and mild. Many episodes of PID go undetected because the woman or her health care provider fails to recognize the implications of mild or nonspecific symptoms. Because there are no precise tests for PID, a diagnosis is usually based on clinical findings. If symptoms such as lower abdominal pain are present, a health care provider should perform a physical examination to determine the nature and location of the pain and check for fever, abnormal vaginal or cervical discharge, and for evidence of gonorrheal or chlamydial infection. If the findings suggest PID, treatment is necessary.

The health care provider may also order tests to identify the infection-causing organism (e.g., chlamydial or gonorrheal infection) or to distinguish between PID and other problems with similar symptoms. A pelvic ultrasound is a helpful procedure for diagnosing PID. An ultrasound can view the pelvic area to see whether the fallopian tubes are enlarged or whether an abscess is present. In some cases, a laparoscopy may be necessary to confirm the diagnosis. A laparoscopy is a surgical procedure in which a thin, rigid tube with a lighted end and camera (laparoscope) is inserted through a small incision in the abdomen. This procedure enables the doctor to view the internal pelvic organs and to take specimens for laboratory studies, if needed.
How is PID treated?

PID is commonly treated with several types of antibiotics. A health care provider will determine and prescribe the best therapy. However, antibiotic treatment does not reverse any damage that has already occurred to the reproductive organs. If a woman has pelvic pain and other symptoms of PID, it is critical that she seek care immediately. Prompt antibiotic treatment can prevent severe damage to reproductive organs. The longer a woman delays treatment for PID, the more likely she is to become infertile or to have a future ectopic pregnancy because of damage to the fallopian tubes.

Because of the difficulty in identifying organisms infecting the internal reproductive organs and because more than one organism may be responsible for an episode of PID, PID is usually treated with at least two antibiotics that are effective against a wide range of infectious agents. These antibiotics can be given by mouth or by injection.  The symptoms may go away before the infection is cured. Even if symptoms go away, the woman should finish taking all of the prescribed medicine. This will help prevent the infection from returning. Women being treated for PID should be re-evaluated by their health care provider three days after starting treatment to be sure the antibiotics are working to cure the infection. In addition, a woman’s sex partner(s) should be treated to decrease the risk of re-infection, even if the partner(s) has no symptoms. Although sex partners may have no symptoms, they may still be infected with the organisms that can cause PID.

Hospitalization to treat PID may be recommended if the woman (1) is severely ill (e.g., nausea, vomiting, and high fever); (2) is pregnant; (3) does not respond to or cannot take oral medication and needs intravenous antibiotics; (4) has an abscess in the fallopian tube or ovary (tubo-ovarian abscess); or (5) needs to be monitored to be sure that her symptoms are not due to another condition that would require emergency surgery (e.g., appendicitis). If symptoms continue or if an abscess does not go away, surgery may be needed. Complications of PID, such as chronic pelvic pain and scarring are difficult to treat, but sometimes they improve with surgery.