Quick answer
What is pelvic inflammatory disease?
Pelvic inflammatory disease (PID) is infection and inflammation of the womb, fallopian tubes, and ovaries — usually caused by untreated chlamydia or gonorrhoea spreading upward. Symptoms include lower abdominal pain, fever, painful sex, and unusual discharge — but can be mild. Needs prompt antibiotics — often two antibiotics together. Delayed treatment causes infertility and ectopic pregnancy risk. See a GP or sexual health clinic urgently if you have pelvic pain with STI risk.
Pelvic inflammatory disease (PID)
Pelvic inflammatory disease (PID) is infection and inflammation of the female upper reproductive tract — womb (endometrium), fallopian tubes, and ovaries. It is a serious complication of sexually transmitted infections — especially chlamydia and gonorrhoea — and a major preventable cause of infertility and ectopic pregnancy in the UK.
How PID happens
Bacteria travel up from the cervix into the upper genital tract:
Most common pathogens:
- Chlamydia trachomatis
- Neisseria gonorrhoeae
- Mycoplasma genitalium (increasingly recognised)
- Anaerobic bacteria from vaginal flora
Risk factors:
- age under 25
- new or multiple partners
- no condom use
- previous PID
- recent IUD insertion (first 3 weeks)
- prior procedures — abortion, miscarriage management
Symptoms — do not ignore mild pain
Classic:
- lower abdominal/pelvic pain — bilateral, dull or cramping
- deep dyspareunia — pain during sex
- abnormal vaginal discharge — yellow/green, offensive
- postcoital or intermenstrual bleeding
- fever, malaise
- painful urination
Mimics: appendicitis, ectopic pregnancy, ovarian cyst rupture — urgent assessment distinguishes.
Silent PID: Some women have minimal symptoms yet tubal scarring develops — infertility is first sign.
Complications
| Complication | Consequence |
|---|---|
| Tubal scarring | Infertility |
| Ectopic pregnancy | Life-threatening if ruptures |
| Chronic pelvic pain | Long-term disability |
| Tubo-ovarian abscess | Hospital admission, surgery |
| Fitz-Hugh-Curtis syndrome | Liver capsule inflammation — right upper pain |
Each PID episode increases damage — same-day antibiotics when suspected.
Diagnosis
Clinical diagnosis — tests support but do not wait for results if typical picture:
- history and examination — cervical motion tenderness, adnexal tenderness
- high vaginal swab — chlamydia, gonorrhoea, Mycoplasma
- endocervical swabs
- pregnancy test — exclude ectopic
- blood tests — CRP, WCC
- ultrasound — tubo-ovarian abscess, alternative diagnosis
Laparoscopy — gold standard but invasive — reserved for uncertain or severe cases.
Treatment
Outpatient (mild-moderate PID)
Typical regimen (BASHH):
- Doxycycline 100mg twice daily for 14 days
- Metronidazole 400mg twice daily for 14 days
- plus ceftriaxone 500mg IM single dose if gonorrhoea not excluded
Alternative if doxycycline unsuitable — clinic selects.
Inpatient (severe PID)
- IV antibiotics
- abscess — drainage or surgery
- pregnancy — adjusted regimens — specialist care
- no response in 72 hours — reconsider diagnosis, imaging
After treatment
- follow-up 72 hours — should improve; if not, review
- test of cure for chlamydia/gonorrhoea at 3 months
- partner treatment mandatory
- no sex until completion
PID and fertility
Honest statistics:
- 1 in 10 women with PID experience infertility
- risk higher with repeated episodes, delayed treatment, severe disease
Trying to conceive after PID:
- GP referral if not pregnant after 12 months (under 36) or 6 months (over 36)
- early ectopic pregnancy awareness — positive test plus pain needs scan
Prevention
- regular STI testing — chlamydia often silent
- condoms with new partners
- chlamydia screen before IUD fitting
- prompt treatment of STIs
PID vs endometriosis
Both cause pelvic pain and painful sex — different mechanisms:
- PID — acute infection, fever, discharge — antibiotics help
- Endometriosis — chronic cyclical pain — no fever/discharge pattern
Sometimes coexist — specialist untangles.
PID is a medical emergency for fertility — pelvic pain plus STI risk means same-day antibiotics, not wait-and-see.
Common questions
- What causes pelvic inflammatory disease?
- Bacteria ascending from cervix to upper reproductive tract — most often chlamydia or gonorrhoea; sometimes bacteria from vagina after procedures (IUD insertion, miscarriage, abortion) or childbirth. Multiple sexual partners and not using condoms increase risk. Not caused by poor hygiene alone.
- How do I know if I have PID?
- Lower tummy pain (often both sides), deep pain during sex, fever, unusual vaginal discharge, bleeding between periods or after sex, pain urinating, feeling unwell. Some women have mild or no symptoms — infertility discovered later. Examination — tenderness on moving cervix — suggests PID.
- Can PID cause infertility?
- Yes — inflammation scars fallopian tubes, blocking egg and sperm meeting. Risk rises with each PID episode and delay in treatment. Roughly 1 in 10 women with PID become infertile — higher after repeated or severe PID. Ectopic pregnancy risk also increases.
- How is PID treated?
- Antibiotic combinations — outpatient often doxycycline plus metronidazole for 14 days, sometimes with single-dose ceftriaxone injection for gonorrhoea cover. Severe illness, pregnancy, or abscess — hospital admission for IV antibiotics and possible surgery. No sex until treatment completed and partners treated.
- Can I get PID from an IUD?
- Slight risk in first 3 weeks after coil insertion — screening for chlamydia before fitting reduces risk. IUD can usually stay in place during PID treatment unless not improving.
- Does my partner need treatment if I have PID?
- Yes — male partners should be tested and treated for chlamydia/gonorrhoea even without symptoms — prevents reinfection. Contact tracing through sexual health clinic.