Summary: What is endometriosis?

According to Endometriosis UK, there are different kinds of endometriosis, including:

• Superficial endometriosis (SE)
• Deep infiltrating disease (>5mm deep into the tissue).
• Extra-pelvic endometriosis found outside of the pelvic cavity.

Women of any age can be affected by endometriosis, but it is rare for the condition to manifest before a girl has her first period. In summary, it affects:

• 1 in 10 women and people assigned female at birth
• up to 50% of infertile women
• those of reproductive age (puberty to menopause)
• people after menopause
• those with a close relative who has it.

• takes an average of 8 years to be diagnosed
• 50% of women with infertility may have endometriosis
• is the second most common gynaecological condition in the UK
• costs the UK economy £8.2 billion each year
• no known cause and no cure, but there are several treatments
• often mistaken for IBS (irritable bowel syndrome).

Symptoms vary and not everyone has them. Some may not realise their pain isn’t normal.

Typical signs include:

• painful periods (may be heavy or have a normal flow)
• chronic pelvic pain (on and off or constant)
• pain during or after sex
• pain when urinating or opening bowels (sometimes with blood in urine or stools)
• fatigue
• depression (often due to delays in diagnosis or infertility)
• infertility
• pain in caesarean section scar or cyclical lump
• back, leg or shoulder tip pain
• chest pain or a cough that comes and goes with the menstrual cycle.

Be aware if someone has:

• period pain that affects daily life
• pain before, during or after periods
• pain during sex
• ongoing pelvic pain
• pain on passing urine or opening bowels
• problems getting pregnant.

Endometriosis can be present even if hormonal treatment is helping with symptoms. A diagnosis is important when it comes to understanding long-term effects and future fertility.

Teenagers who suffer with painful periods, experience fainting or collapse when having a period, or who miss school because of the symptoms, should be considered as possibly suffering from the condition.

In primary care:

• take a history and do an abdominal exam and pelvic ultrasound (NICE guidelines)
• if symptoms persist despite a normal exam, consider a referral.

Refer to a specialist or endometriosis service if:

• diagnosis is unclear
• treatment doesn't work or isn’t suitable
• the patient asks for a referral
• there are fertility concerns
• doctors/specialists suspect endometriosis outside the pelvis (for example, bowel, bladder)
• hormonal treatments are not effective or tolerated
• symptoms impact daily life or return after treatment.

BSGE (British Society for Gynaecological Endoscopy) accredits specialist centres. The BSGE includes multidisciplinary teams and liaises with pain and fertility services. Patients under 18 should be referred to paediatric or adolescent services.

While awaiting referral, patients can try or be offered the following:

• Pain relief (analgesics): For example, paracetamol or NSAIDs (non-steroidal anti-inflammatory drugs), especially during periods.

• Oral hormonal treatments:

• Combined contraceptive pill (continuously or in cycles).
• Progesterone-only options (for example, norethisterone, medroxyprogesterone acetate, Dienogest).

• Intra-uterine hormonal device (IUS): For example, Mirena, for long-term pain relief.

Not everyone will become period-free with hormonal treatment, and pain may persist.

Investigations may include:

• pelvic ultrasound or MRI
• specialist scans to look for deep endometriosis.

Laparoscopy (keyhole surgery) is no longer the first-line diagnostic tool. It’s used when imaging is inconclusive or treatments haven’t worked. Laparoscopy diagnosis needs tissue testing for confirmation. However, a negative test does not exclude endometriosis.

Cases of complex endometriosis (or suspected severe endometriosis) should be sent to a specialist BSGE-accredited endometriosis centre.

These women can access specialist gynaecologists and a clinical nurse specialist (CNS) who work in conjunction with general surgeons and urologists.

A full list of accredited specialist endometriosis centres in the UK can be found on the BSGE website.

• Endometriosis UK.
• BSGE – Find a specialist centre.
• NICE guidelines on endometriosis.
• WHO fact sheet.

The full PDF explores this topic in more detail. The publication may include case studies, images, tables, good practice checklists, glossaries and suggested questions to ask patients. You’ll also find a concise list of references and links to useful organisations and websites.