Symptoms NHS guidelines say to take seriously
NHS guidelines NG73 (Endometriosis: diagnosis and management) tells GPs to suspect endometriosis when a woman or person assigned female at birth presents with one or more of:
- Chronic pelvic pain.
- Period-related pain (dysmenorrhoea) that affects daily activities and quality of life.
- Deep pain during or after sex (dyspareunia).
- Period-related or cyclical gastrointestinal symptoms, especially painful bowel movements.
- Period-related or cyclical urinary symptoms, especially blood in urine or pain passing urine.
- Infertility associated with one or more of the above.
The NHS guideline NG73 pathway
NHS guidelines recommend:
- A focused history and abdominal/pelvic examination, though absence of findings does not rule endometriosis out.
- Considering transvaginal ultrasound to look for ovarian endometriomas or signs of deep endometriosis (and where TVUS isn't appropriate, transabdominal).
- Referring to a gynaecologist for further assessment and investigation when initial management has not worked or when symptoms are severe.
- Referring to a specialist endometriosis service if deep endometriosis involving bowel, bladder or ureter is suspected.
What to bring to your GP
- A 12-week pain and bleeding diary: dates, severity 0 to 10, what stopped you doing, painkillers taken.
- Cycle dates and length over those 12 weeks.
- Any bowel or bladder symptoms with timing relative to your period.
- Impact on work, education, sex, sleep, concrete, not adjectives.
Referral wording
Sample only. For illustration.
Scans and laparoscopy
Transvaginal ultrasound is often the first imaging investigation, looking for endometriomas and signs of deeper disease. MRI is added where deep infiltrating endometriosis is suspected. The definitive diagnosis is laparoscopy with histological confirmation of endometrial-like tissue outside the uterus.
If your GP won't refer, see our guide on refused referrals. A formal, NG73-cited letter is the single most effective lever for a delayed endometriosis referral. Get my GP letter in 3 minutes.
Frequently asked questions
What is the only definitive way to diagnose endometriosis?
Laparoscopy with histological confirmation remains the diagnostic gold standard for endometriosis. NHS guideline NG73 says the absence of findings on examination, ultrasound or MRI does not rule out endometriosis, referral should still be considered.
How long does diagnosis usually take?
Endometriosis UK, in The State of Endometriosis Care in the UK (published February 2026, survey of 3,075 people diagnosed since 2015, fieldwork September to October 2025), puts the UK average at 9 years and 4 months from the first GP visit with symptoms to diagnosis. That is a diagnostic delay figure, not an NHS waiting-list time. The pathway can be much shorter if the GP refers to gynaecology early under NHS guideline NG73.
Can endometriosis be diagnosed on a scan?
Transvaginal ultrasound and MRI can identify some forms (e.g. ovarian endometriomas, deep infiltrating endometriosis), but a normal scan does not exclude the diagnosis, superficial peritoneal disease can only be confirmed surgically.
Do I have to try hormonal treatment first?
NHS guidelines recommend offering hormonal management for symptoms while investigations are arranged, but it is not a precondition for referral. If your GP is making it one, ask for the clinical reasoning in writing.