Medical maps: pelvic pain

Ovarian cyst.

In the last medical map we talked about gynaecological bleeding. Now let’s move onto another key symptom: pain.

I’ll talk about pelvic pain rather than gynaecological pain, because it is important to be aware of non-gynaecological causes of lower abdominal pain.

The pattern of pain is important, and broadly speaking, there are three:

  • Painful periods (dysmenorrhoea) – pain occurring immediately before or during menstruation
  • Painful intercourse (dyspareunia) – age of presentation can be helpful to distinguish between likely causes, but most causes can occur at any age
  • Pelvic pain unrelated or loosely related to periods/intercourse 

Note that a single pathology can result in more than one of these presenting complaints. For example, endometriosis (endometrial tissue outside of the uterus) can cause both dysmenorrhoea and dyspareunia. Pelvic inflammatory disease (PID; defined as infection of the upper female reproductive tract including endometritis, salpingitis and oophoritis) can cause painful intercourse, painful periods or general pelvic pain.

Let’s have a look at these specific symptoms in more detail:

  • Painful periods
    • Primary – no identifiable cause (90% of cases).
    • Secondary – there is an underlying cause (remaining 10% of cases). I remember AEIOU.
      • A: adenomyosis (think of it as endometriosis in the myometrium)
      • E: endometriosis
      • I: infections (infective vaginitis, cervicitis, PID) and IUDs
      • O: other (psychological)
      • U: uterine leiomyomas
  • Painful intercourse
    • Generally premenopausal
      • Endometriosis
      • Vulvodynia (persistent unexplained pain in the vulva)
      • PID (classically young sexually active women)
    • Generally postmenopausal
      • Urogenital atrophy (aka atrophic vaginitis)
    • Any age
      • Infections – infective vaginitis, cervicitis, PID, UTIs
      • Vaginismus (persistent muscular tightening of the vagina whenever penetration is attempted)
      • Trauma/inadequate lubrication
  • Pain unrelated or loosely related to periods/intercourse – here we need to think a bit more broadly:
    • Pregnancy-related
      • Early pregnancy pain (ectopic, miscarriage, molar)
      • Late pregnancy pain (abruption, labour)
    • Gynaecological, unrelated to pregnancy (but can occur during pregnancy!)
      • Ovarian cyst
      • Ovarian torsion
      • Cancers (endometrial, ovarian)
      • Infective vaginitis, cervicitis, PID
    • Non-gynaecological
      • Appendicitis
      • IBD, IBS
      • UTIs

I also want to discuss some confusing terms here: the gynae ‘itis’ diseases,  including vaginitis, cervicitis, endometritis, salpingitis and oophoritis. All of these can cause pelvic pain.

img_0918

Infections of the female reproductive tract.

Some key points:

  • Inflammation (=itis) of the reproductive tract is generally the result of an infection 
    • Key exception: atrophic vaginitis in (generally) post-menopausal women due to low levels of oestrogen
  • Whether ‘cervicitis’ ever truly exists in isolation is unclear
    • It probably doesn’t; it will occur in the context of vaginitis and/or PID
  • PID describes infection of the upper female reproductive tract (above the cervix) – including the uterus (endometritis and myometritis), fallopian tubes (salpingitis) and/or ovaries (oophoritis)
    • PID is thought to be due to ascending infection from the vagina/cervix
    • In practice, clinicians sometimes distinguish between endometritis and PID*, where PID strictly refers to adnexal involvement (fallopian tubes and ovaries)
  • Clinically, the diagnosis of PID (and therefore endometritis/salpingitis/oophoritis) is based on history (young, sexually active woman with fever/discharge/lower abdo pain), examination (cervical motion tenderness) and purulent discharge
    • So, PID is a clinical diagnosis… whereas to definitively diagnose any one of its ‘itis’ components, a biopsy would be needed (showing organisms/neutrophils)

*There is some debate about whether endometritis is a separate entity to PID or whether they are part of the same condition. There is no point over-complicating things, so I would just lump endometritis with PID.

I hope that has vaguely cleared things up. The take-home: PID is infection of the upper reproductive tract (above the cervix), and includes endometritis, salpingitis and oophoritis. 

Anyway, after that brief (?!) segway, here is the medical map for gynaecological pain:

img_0921

Medical map for pelvic pain. ‘Mittelschmerz’ is a term given to mid-cycle pain some women experience associated with ovulation. Click to zoom.

I hope this is useful! Feel free to email me any questions or to suggest improvements/edits.

Leave a Reply