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Health condition · Clinically reviewed

Endometriosis and adenomyosis, a modern UK guide to pain, bleeding and fertility.

Around 1 in 10 women live with endometriosis, and adenomyosis is increasingly recognised alongside it. A stepped plan, better imaging and BSGE-accredited centres are closing the diagnostic delay.

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A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against NICE NG73, ESHRE 2022, BSGE and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK practice including GnRH antagonists (Ryeqo), MRI protocols and BSGE-accredited endometriosis centres.

Key facts

Endometriosis and adenomyosis at a glance.

The essentials in plain English, how these conditions differ, how they overlap and how they are managed in the UK today.

  • How common

    Around 1 in 10 women of reproductive age are affected, a major cause of chronic pelvic pain and subfertility.

  • Endometriosis

    Endometrial-like tissue outside the uterus, on peritoneum, ovaries, pouch of Douglas, bowel, bladder and rarely diaphragm or lung.

  • Adenomyosis

    Endometrial glands and stroma inside the myometrium itself, either diffuse or focal (adenomyoma).

  • Diagnostic delay

    On average 7 to 10 years from first symptoms to diagnosis, a delay specialist services aim to close.

  • Staging

    ASRM and AAGL stages I to IV, with deep infiltrating disease (DIE) managed in commissioned centres.

  • First imaging

    Transvaginal ultrasound is the first-line scan, with pelvic MRI reserved for deep disease and surgical planning.

Why this guide matters

Two overlapping conditions, one coordinated plan.

Endometriosis and adenomyosis often co-exist, and modern UK care treats them together, with imaging, hormonal suppression and expert surgery where needed.

  • Imaging has caught up

    Transvaginal ultrasound and specialist pelvic MRI now detect adenomyosis and deep endometriosis without the delays of the past.

  • Medical options have expanded

    Alongside the pill and the LNG-IUS, oral GnRH antagonists like Ryeqo now offer rapid, well-tolerated hormonal control.

  • Specialist surgery is centralised

    Deep infiltrating disease is managed in BSGE-accredited centres with pain, colorectal, urology and fertility teams on hand.

How the diagnosis is made

From first symptoms to a clear plan.

The steps a UK GP or gynaecologist will normally follow, in order, so you know what to expect and when a BSGE-accredited centre is right.

  1. 01

    Assessing

    Symptom history and pain diary

    Cyclicity, dysmenorrhoea, deep dyspareunia, dyschezia, bladder symptoms and fertility goals mapped over one to two cycles.

  2. 02

    Assessing

    Clinical examination

    Bimanual and speculum exam looking for tender uterosacral nodules, a fixed retroverted uterus or a bulky tender uterus in adenomyosis.

  3. 03

    Assessing

    Transvaginal ultrasound

    Endometriomas, adenomyosis features (globular uterus, junctional zone changes, myometrial cysts and venetian-blind shadowing) and adhesions.

  4. 04

    Confirming

    Pelvic MRI

    Specialist protocol for deep infiltrating endometriosis, adenomyosis mapping and pre-surgical planning.

  5. 05

    Confirming

    CA-125 in context

    Non-diagnostic and often raised in menstruation, useful only alongside imaging and clinical picture.

  6. 06

    Planning

    Referral to a BSGE centre

    Deep or complex disease is managed in a BSGE-accredited endometriosis centre with a full multi-disciplinary team.

  7. 07

    Planning

    Laparoscopy with biopsy

    Still the histological gold standard, no longer required to start medical treatment per NICE NG73.

Typical timeline: first appointment to a specialist plan in weeks, once suspected.

Symptoms

What these conditions actually feel like.

The classic pattern is cyclical pain that worsens over years, with bleeding, bowel, bladder and fertility overlap. Some features flag deep or thoracic disease.

  • Severe progressive period pain

    Dysmenorrhoea that is worsening year on year, often starting days before the bleed and lasting into it.

  • Chronic pelvic pain

    Non-cyclical pain that persists between periods, often described as dragging, burning or deep aching.

  • Deep dyspareunia

    Pain with deep penetration, often positional and worse premenstrually. See our dyspareunia guide.

  • Heavy menstrual bleeding

    Especially prominent in adenomyosis and a common overlap with fibroids. See our heavy periods guide.

  • Bowel and bladder symptoms

    Cyclical dyschezia, rectal bleeding, urinary urgency or cyclical haematuria suggest deep disease.

  • Subfertility

    Difficulty conceiving is common, either from tubo-ovarian distortion, endometriomas or altered pelvic environment.

  • Fatigue and mood impact

    Chronic pain and blood loss drive fatigue, low mood and a real quality-of-life burden.

  • Rare thoracic disease

    Cyclical haemoptysis, shoulder-tip pain or catamenial pneumothorax point to thoracic endometriosis.

Treatment

How these conditions are treated in the UK.

Analgesia and hormonal suppression first, expert excision surgery for deep disease, and coordinated fertility and mental-health support throughout.

  • Analgesia and pain psychology

    Paracetamol and NSAIDs first line, with tricyclics, gabapentinoids and a specialist pain psychology clinic for refractory pain.

  • Combined hormonal contraception

    Combined pill, patch or ring used continuously to suppress cyclicity, first-line hormonal option for many.

  • Progestogen options

    POP, implant, injection or the LNG-IUS (Mirena), which is particularly effective for adenomyosis-related bleeding and pain.

  • GnRH analogues with add-back

    Leuprolide, goserelin or triptorelin in short courses, with add-back HRT to protect bone and reduce vasomotor symptoms.

  • GnRH antagonists

    Oral relugolix with estradiol and norethindrone (Ryeqo), NICE-approved for endometriosis pain and heavy bleeding in fibroids.

  • Laparoscopic excision

    Preferred over ablation for deep disease, performed in BSGE-accredited centres with colorectal and urology input as needed.

  • Uterine artery embolisation

    Selective option for symptomatic adenomyosis where surgery is not preferred, delivered by interventional radiology.

  • Hysterectomy with or without BSO

    For refractory adenomyosis or severe endometriosis once fertility is complete, ideally laparoscopic in expert hands.

What this guide is based on

The sources behind every claim on this page.

UK national guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP or gynaecologist knows your history and can tell you which parts apply to you. If in doubt, get seen.

  • NICE NG73. Endometriosis: diagnosis and management.

  • ESHRE 2022. Guideline on the management of endometriosis.

  • British Society for Gynaecological Endoscopy (BSGE). Endometriosis centre standards.

  • NICE TA advice on relugolix/estradiol/norethindrone (Ryeqo) for endometriosis and fibroids.

  • RCOG Green-top and patient information on endometriosis and adenomyosis.

Red flags

When these conditions need urgent attention.

Most symptoms are managed in planned care. These are the situations that are not, and where an urgent specialist opinion is needed.

  • Acute severe pain with collapse

    Sudden severe pelvic pain with faintness may indicate a ruptured endometrioma or ovarian torsion, an emergency needing hospital assessment.

  • Bowel obstruction symptoms

    Persistent vomiting, absolute constipation and abdominal distension in known deep disease need urgent surgical review.

  • Ureteric obstruction

    Silent hydronephrosis can occur in deep endometriosis, so unexplained loin pain or renal impairment warrants urgent imaging.

  • Cyclical haemoptysis

    Coughing blood around periods suggests thoracic endometriosis and needs specialist respiratory and gynaecology review.

  • Catamenial pneumothorax

    Recurrent pneumothorax timed with menstruation needs urgent assessment and thoracic multi-disciplinary input.

  • Post-menopausal pelvic pain or bleeding

    New pelvic pain or bleeding after menopause is never assumed to be endometriosis and needs urgent gynaecology assessment.

  • Severe mood impact

    Chronic pain drives real psychological distress, and low mood or suicidal thoughts need urgent GP or crisis support.

  • Suspected malignant transformation

    Rare but recognised, especially in long-standing endometriomas, so growing complex ovarian cysts warrant specialist imaging.

  • Pregnancy with known deep disease

    Antenatal care benefits from early liaison with the endometriosis team, especially if there is bowel or bladder involvement.

Living with it

A long-term condition, with a clear ladder of care.

Four things that make the biggest day-to-day difference, from tracking symptoms to leaning on charities like Endometriosis UK.

A quiet reminder

Consistency and coordination beat one-off fixes.

Layered care, kept up over months, does far more than any single treatment used in isolation.

  1. 01 Track

    Keep a pain and cycle diary

    A month or two of dated notes on pain, bleeding, bladder and bowel symptoms is the most useful thing to bring to any appointment.

  2. 02 Team

    Ask for the right team

    Deep or complex disease belongs in a BSGE-accredited endometriosis centre with pain, colorectal, urology and fertility support.

  3. 03 Layer

    Layer treatments patiently

    Hormonal suppression, targeted pain care, physiotherapy and psychology often work best together rather than in isolation.

  4. 04 Support

    Lean on charities and peers

    Endometriosis UK and the Adenomyosis Advice Association offer expert-reviewed information and community that clinicians cannot replace.

Frequently asked

Everything we get asked about endometriosis and adenomyosis.

Quick answers on diagnosis, imaging, hormonal options, surgery and fertility.

  • What is endometriosis?

    Endometriosis is a condition where tissue similar to the lining of the uterus grows outside it, most often on the peritoneum, ovaries and pelvic ligaments, and less commonly on bowel, bladder, ureter, diaphragm and rarely lung. It is oestrogen-dependent, inflammatory and a major cause of pelvic pain and subfertility.

  • What is adenomyosis and how is it different?

    Adenomyosis is endometrial glands and stroma inside the muscular wall of the uterus itself. It typically causes heavy, painful periods and a bulky tender uterus. Endometriosis sits outside the uterus, adenomyosis sits within its wall, and the two often co-exist.

  • Why does diagnosis take so long?

    Symptoms overlap with common gynaecological and gastrointestinal problems, and imaging can look normal in early disease. UK average delay is 7 to 10 years, which is why NICE NG73 encourages earlier suspicion, transvaginal ultrasound and referral to specialist centres.

  • Do I need a laparoscopy to be diagnosed?

    No. NICE NG73 makes it clear that medical treatment can be started based on symptoms and imaging, without a diagnostic laparoscopy. Laparoscopy with biopsy remains the histological gold standard and is often combined with treatment of deep disease in a BSGE-accredited centre.

  • What are the newer medical options?

    GnRH antagonists such as relugolix combined with estradiol and norethindrone (Ryeqo) are now NICE-approved for endometriosis pain and for heavy bleeding in fibroids. They give rapid oestrogen suppression with built-in add-back, avoiding the flare and vasomotor issues of older GnRH analogues.

  • Will surgery affect my fertility?

    Expert excision by a BSGE-accredited surgeon aims to preserve ovarian tissue and restore anatomy, and can improve natural conception rates. In more severe disease or where fertility is a priority, coordinated care with a reproductive medicine team and consideration of IVF is central.

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