But most people with PID who complete their course of antibiotics have no long-term problems.
Sometimes you can experience repeated episodes of PID. This is known as recurrent pelvic inflammatory disease.
The condition can return if the initial infection isn't entirely cleared.
This is often because the course of antibiotics wasn't completed or because a sexual partner wasn't tested and treated.
If an episode of PID damages the womb or fallopian tubes, it can become easier for bacteria to infect these areas in the future, making it more likely that you'll develop the condition again.
Repeated episodes of PID are associated with an increased risk of infertility.
PID can sometimes cause collections of infected fluid called abscesses to develop, most commonly in the fallopian tubes and ovaries.
Abscesses may be treated with antibiotics, but sometimes laparoscopic surgery (keyhole surgery) may be needed to drain the fluid away.
The fluid can also sometimes be drained using a needle that's guided into place using an ultrasound scan.
Sometimes PID can lead to long-term (chronic) pain around your pelvis and lower abdomen, which can be difficult to live with and lead to further problems, such as depression and difficulty sleeping (insomnia).
If you develop chronic pelvic pain, you may be given painkillers to help control your symptoms.
Tests to determine the cause may be carried out.
If painkillers don't control your pain, you may be referred to a pain management team or a specialist pelvic pain clinic.
An ectopic pregnancy is when a fertilised egg implants itself outside of the womb, usually in one of the fallopian tubes.
If PID infects the fallopian tubes, it can scar the lining of the tubes, making it more difficult for eggs to pass through.
If a fertilised egg gets stuck and begins to grow inside the tube, it can cause the tube to burst, which can sometimes lead to severe and life-threatening internal bleeding.
If you're diagnosed with an ectopic pregnancy, you may be given medication to stop the egg growing or have surgery to remove it.
As well as increasing your risk of having an ectopic pregnancy, scarring or abscesses in the fallopian tubes can make it difficult for you to get pregnant if eggs can't pass easily into the womb.
You could become infertile as a result of the condition. There's a higher risk of infertility if you delay treatment or had repeated episodes of PID.
But a long-term study in the US showed that people who'd been successfully treated for PID had the same pregnancy rates as the rest of the population.
Blocked or damaged fallopian tubes can sometimes be treated with surgery.
If this isn't possible and you want to have children, you may want to consider an assisted conception technique, such as IVF.
IVF involves surgically removing eggs from the ovaries and fertilising them with sperm in a laboratory, before putting the fertilised eggs into the womb.
This technique can help you get pregnant if you can't have children naturally. But the success rate varies, depending on your age and other factors.
