Pelvic inflammatory disease, also known as PID is a health condition that affects different parts of the female reproductive system, including the ovaries, fallopian tubes, womb and the genital tract. The root cause of this condition is usually a bacterial infection and it is not uncommon for multiple bacteria strain to be present at the same time. As such, PID is not classified as a sexually transmitted infection, but it is caused by one in a majority of cases (usually chlamydia or gonorrhoea).

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The onset of the condition is marked by a number of symptoms including pelvic pain, painful urinations and changes in the menstrual cycles like bleeding between periods or more intensive periods. These symptoms can, in some cases, be rather mild go unnoticed for long periods of time. If left untreated, pelvic inflammatory disease can lead to further complications including abscesses, chronic pelvic pain and in some cases even infertility.

In order to diagnose the condition, a medical expert will usually need to perform a pelvic examination and conduct a laboratory analysis afterwards. Swab samples which are simple and painless to take are the main material used for further analysis. In addition, doctor might request additional diagnostic procedures such as taking blood or urine samples or an ultrasound scan. In either case, all the diagnostic methods used are completely painless and safe.

When discovered early, PID can be easily treated with a course of antibiotics. However, more severe cases or those that were discovered only after the infection has already progressed might require hospitalization in order to be properly treated.

What causes pelvic inflammatory disease (PID)?

As briefly mentioned, PID is caused by a bacterial infection and there are multiple strains which can be responsible for the onset of this condition – these may be bacteria which are the root cause of STIs such as chlamydia or gonorrhoea, but they don’t necessarily have to be. In a majority of diagnosed cases, pelvic inflammatory disease is caused by simultaneous presence of multiple species of bacteria within the female reproductive system.

However, Chlamydia trachomatis, the strain responsible for genital chlamydia and Neisseria gonorrhoeae which causes gonorrhoea are present in a significant portion of those affected, implicating a strong correlation between STIs and PID.

According to statistical research conducted by the NHS, around a quarter of all diagnosed PID cases are result of untreated chlamydia or gonorrhoea. Contrary to this, CDC’s official info states that these STIs might be responsible for as much as 33% to 50% of PID cases.1

No matter which type of bacteria is the culprit, this condition is always brought on by the migration of microbes from the vagina, past the cervix and into the upper genital tract. These microorganisms can be harmless and naturally present within the vagina, but become problematic once they are introduced into other parts of the reproductive system. This underlines the fact that while STIs are often to blame, this is not true for all cases.

Infection can also occur if the cervix is damaged over the course of childbirth or miscarriage. There are also certain medical procedures which require cervix to be opened (for example, in order to fit a contraceptive coil) which is another risk factor. In addition to this, anything that might cause bacterial vaginosis by disrupting the balance of the vaginal fauna (such as douching) can also kick-start PID too.

Who is at risk of developing PID?

Women who are sexually active are at a significantly higher risk, and the same goes for those women which struggled with pelvic inflammatory disease in the past. However, despite the clear presence of these high-risk groups, any woman can get affected, regardless of whether she is sexually active or not.

Public Health England conducted a study in 2015 which resulted in the conclusion that the highest rate of diagnosis in GP settings was among women aged between 20 and 24, while in hospital settings, the highest diagnosis rate was among those aged 35 to 44. In the broader age group 15-44, PHE reports 176 diagnosis per 100.000 women in primary care setting and additional 241 cases per 100.000 women in hospital setting.

What are the symptoms of pelvic inflammatory disease?

The symptoms of PID are well-known, but they can still be mistaken for STDs or other urinary problems. In addition to that, when the symptoms are subtle, many women might miss them completely. They include:

  • Pain in the lower abdomen
  • Fever
  • Vaginal discharge
  • Heavier and more intensive periods
  • Bleeding after sex or between periods
  • Pain and burning sensation when urinating
  • Changes in the colour and consistency of vaginal discharge
  • Nausea and vomiting (in severe cases or advanced infection)

Can PID cause further complications?

There are multiple potentially serious health conditions and complications that can be brought on by untreated pelvic inflammatory disease. These include:

  • Recurrent PID caused by the initial infection damaging the reproductive organs, making them more vulnerable to secondary infections
  • Long-term pelvic pain
  • Abscesses in the fallopian tubes or ovaries
  • Infertility in cases when infection causes lasting damage of the fallopian tubes (this occurs in roughly 1 in 10 cases of PID)
  • Ectopic pregnancy (pregnancy developing outside of the womb, most typically in the fallopian tubes)

As is the case with most health conditions, if PID is diagnosed and treated early on, the chances of complications are dramatically lower.

How is pelvic inflammatory disease diagnosed?

There are several tests that doctor might conduct in order to determine whether PID is present and in order to rule out other possible conditions. Most common methods utilized by medical professionals include:

  • Gynaecological exam (usually the first stage of the diagnostic process)
  • Cervical swab (in order to check whether chlamydia or gonorrhoea might be present)
  • Urine and blood tests (confirming the diagnosis and ruling out other causes)
  • Ultrasound and pregnancy tests (the same as above)
  • Laparoscopy – a procedure when small incisions are made in the abdomen and a tiny camera is inserted in order to check the area for signs of inflammation (very rarely used method)

How is PID treated?

The combination antibiotic treatment is the most common approach to treating pelvic inflammatory disease, with both tablets and injections being relatively commonly prescribed. Factors influencing the doctor’s decision can include severity and nature of the condition (exact strain of bacteria causing it) as well as whether the patient is pregnant.

NICE guidelines advise the following treatment options:

  • Ofloxacin and metronidazole as first-line treatment
  • Ceftriaxone, Cefixime, Doxycycline and metronidazole combination treatment
  • Ceftriaxone (or Cefixime) and Azithromycin

If the infection has significantly progressed or is very sever, hospitalization might be required.

How can I avoid getting PID?

While it is impossible to be sure that you are 100% protected from this condition, there are certain precautions which can significantly lower the risks:

  • Prior to having a high-risk procedure, have an examination to rule out presence of an infection
  • Avoid douching and other practices which might disrupt the balance of vaginal fauna
  • Practicing safe sex with barrier contraception


  1. PID Fact Sheet – CDC