Pelvic Inflammatory Disease (PID): What Is It?

Medically Reviewed by Zilpah Sheikh, MD on April 16, 2024
6 min read

Pelvic inflammatory disease (PID) is an infection that affects one or more of the reproductive organs. These organs include the uterus, ovaries, and fallopian tubes. The cause is often a sexually transmitted infection (STI) such as chlamydia or gonorrhea.

PID is a common illness. About 2.5 million people assigned female at birth in the U.S. will have it at some point in their lives. PID can cause pain in your lower belly and make it harder to have a baby if you don’t treat it.

STIs such as chlamydia and gonorrhea cause most cases of PID. If you have unprotected sex with someone who has one of these infections, the bacteria can travel up your vagina or cervix to your reproductive organs. Another type of STI caused by Mycoplasma genitalium (a bacterium) can also lead to PID.

You can also get exposed to the bacteria that cause PID during:

  • Insertion of an intrauterine device (IUD) for birth control
  • Your period
  • Childbirth
  • An abortion
  • Surgery on your uterus

Less often, the bacteria that cause infections such as the flu, pneumonia, and strep can cause PID.

You might not notice any symptoms of PID early on. But as the infection gets worse, you can have:

  • Pain in your lower belly and pelvis
  • Heavy discharge from your vagina that may be green or yellow and have a bad smell
  • More bleeding than usual during your period
  • Bleeding between periods
  • Pain or bleeding during sex
  • Fever and chills
  • Pain when you pee or trouble peeing
  • Throwing up, or feeling like you’re going to throw up

In some cases, PID can bring on more intense symptoms, and you’ll need to go to the emergency room. Get medical help right away if you have:

  • Severe pain in your lower belly
  • Signs of shock, such as fainting
  • Vomiting
  • Fever higher than 101 F

Your risk for PID is higher if you:

  • Have sex with many partners or your partner has sex with other people, too
  • Douche often
  • Don’t use condoms when you have sex
  • Had PID or an STI in the past
  • Have an IUD
  • Had your tubes tied

Your doctor might ask if you’ve had more than one sex partner in the past and whether you’ve had an STI before. They’ll also ask about your symptoms.

During a pelvic exam, the doctor checks for swelling and pain in your cervix, uterus, or other organs in your pelvis (ovaries and fallopian tubes). They may take a sample of fluid from your vagina and cervix. The sample will go out to a lab, which tests it for STIs such as chlamydia and gonorrhea.

Other tests you might have include:

  • Blood and urine tests to check for STIs and look for signs of other infections
  • An ultrasound to help your doctor see the organs in your pelvis

If the results of these tests don’t confirm PID, you may need a procedure called laparoscopy. The doctor places a thin scope with a light at the end through a small cut in your lower belly to look at your pelvic organs. Or the doctor might take a small sample of tissue from your uterus (a procedure called biopsy) to test for infection.

If the exam or test results suggest PID, your doctor will let you know what treatment you need.

If you have PID, your doctor will most likely prescribe antibiotics to kill the bacteria that caused the infection.

PID medication

Many types of antibiotics treat PID, including ceftriaxone, doxycycline, and metronidazole. You may take more than one type of antibiotic at the same time to help the medicine work better.

Antibiotics can clear up a PID infection, but they can’t get rid of scars that the infection may have left in your pelvis. That’s why it’s important to start treatment early before the infection can cause scars.

Your sex partner should also take antibiotics so they don’t infect you again. Even if your partner has no symptoms, they can still carry the bacteria that cause PID. Don’t have sex until you both have finished treatment and your symptoms have gone away.

The doctor may follow up with you in 3 days to see if your symptoms have improved. If your symptoms don’t improve, you may need a different type of antibiotic. Complete the entire course of medication even if you feel better.

You may need treatment in a hospital if you:

  • Are very sick with symptoms such as a high fever, nausea, and throwing up
  • Can’t take antibiotics
  • Have taken antibiotics, but your symptoms aren’t better
  • Have an abscess, which is a pocket of pus that forms because of an infection in your fallopian tube and ovary
  • Are pregnant
  • Have another problem, such as appendicitis

The hospital staff may give you stronger antibiotics through your vein or by mouth.

PID is easy to treat with antibiotics if you catch it early. But if you don’t start treatment soon enough, the infection could cause scars in your pelvis and complications such as:

Chronic pelvic pain. As much as one-third of women with PID have pain in their pelvis that lasts months or years. The pain happens from inflammation and scars in the pelvis. Having PID more than once increases your risk for chronic pelvic pain.

Trouble getting pregnant. PID causes infertility when it damages the fallopian tubes — the tubes that your eggs travel down to get from your ovaries to your uterus. Women who’ve had PID are about five times more likely to have fertility problems than those who never had PID.

Abscess. A collection of pus called an abscess can form in your reproductive tract. If you don’t treat an abscess, it could turn into a very serious infection.

Pelvic inflammatory disease and pregnancy

PID also increases the risk for an ectopic pregnancy from scars in the fallopian tubes. Because the fertilized egg can’t travel down the damaged tube to implant in the uterus, it could instead implant and grow in the fallopian tube. This type of pregnancy can’t progress to term, and it risks the mother’s life.

PID is an infection of the female reproductive system. Most often, the cause is an STI such as chlamydia or gonorrhea. PID is treatable with antibiotics, but it’s important to treat it quickly. Waiting too long to start treatment could cause serious complications such as infertility and chronic pelvic pain.

Should you tell your partner about PID?

Yes. Tell your partner that you have PID so they can get tested and treated, too. That will lower your risk of getting infected again with the bacteria that caused PID.

Can bacterial vaginosis (BV) cause PID?

Yes. PID most often happens after an STI such as chlamydia or gonorrhea. But infections that aren’t sexually transmitted, such as bacterial vaginosis, can also cause PID. You can get BV when the levels of good and bad bacteria in your vagina are out of balance.

Which antibiotic is best for PID?

A few antibiotics work against PID. You may get a combination of two or three medicines such as ceftriaxone, doxycycline, and metronidazole.