It's 7.40 on a Tuesday in a chilly staff changing room, and Maisie, 26, a trainee nurse, keeps one hand pressed to her stomach while she works out when she can take her next painkiller without missing the start of her shift. Since she was 16, she has been told that periods are meant to hurt. Nearly nine years: that is the average time to diagnosis of endometriosis in the UK — 8 years and 10 months, according to Endometriosis UK's 2024 report on diagnosis times, based on a survey of 4,371 people and ten months longer than in 2020. This guide is not a substitute for medical care, but it might help you shorten that wait.
Endometriosis is still too often dismissed as "bad periods", yet it is a chronic, inflammatory condition — and the NICE guideline asks clinicians to be aware that it "can have a significant physical, sexual, psychological and social impact". This guide draws on that guideline (NG73, last updated in November 2024), NHS information, the Royal College of Obstetricians and Gynaecologists (RCOG) and Endometriosis UK, the national charity.
What is endometriosis exactly?
Endometriosis is a chronic condition in which cells similar to those in the lining of the womb (the endometrium) grow in other parts of the body — most often in the pelvis. Lesions are typically found on the ovaries, the fallopian tubes, the ligaments around the womb and the peritoneum, the thin lining of the pelvis; they can also reach the bladder or the bowel.
This tissue responds to the hormones of the menstrual cycle just as the womb lining does. As the NHS explains, symptoms happen when patches of endometriosis break down and bleed but cannot leave the body. The result is local inflammation and, over time, scar tissue around the lesions.
Endometriosis is not simply a disease of painful periods. It can cause pain at any time of the month, extreme tiredness and low mood — and some people have very few symptoms, only discovering the condition during investigations for difficulty getting pregnant.
Endometriosis in the UK in figures: common and under-recognised
In the UK, endometriosis affects around 1 in 10 women of reproductive age, and Endometriosis UK's facts and figures put the wider picture into numbers:
- 1 in 10 women and those assigned female at birth of reproductive age in the UK have endometriosis.
- 1.5 million people in the UK are living with the condition.
- 8 years and 10 months: the average time to diagnosis in the UK in Endometriosis UK's 2024 survey, up ten months since 2020.
- 30–50%: the prevalence of endometriosis in women with infertility.
- £8.2 billion: the annual cost to the UK economy in treatment, loss of work and healthcare costs.
- 190 million: the number of reproductive-age women affected worldwide, around 10% (World Health Organization).
Endometriosis UK published the report in March 2024, during Endometriosis Action Month, and its survey paints a grim picture of the road to diagnosis. Almost half of respondents (47%) had visited their GP 10 or more times with symptoms before being diagnosed. And 78% had been told by at least one doctor that they were making a fuss about nothing, or something similar. Only 10% said a GP mentioned suspecting endometriosis at their first or second appointment where symptoms were discussed.
Symptoms of endometriosis: when should you see a GP?
Endometriosis symptoms vary considerably from one person to another — one of the main reasons for the diagnostic delay. NICE asks clinicians to suspect endometriosis when someone presents with one or more of the following:
The core symptoms:
- Chronic pelvic pain, defined as pain lasting six months or longer.
- Period pain (dysmenorrhoea) that affects daily activities and quality of life.
- Deep pain during or after sex.
- Period-related bowel symptoms, in particular painful bowel movements.
- Period-related urinary symptoms, in particular blood in the urine or pain passing urine.
- Infertility, in association with one or more of the above.
Other symptoms the NHS lists:
- Heavy periods, where you need to change your pads or tampons every 1 to 2 hours.
- Extreme tiredness (fatigue).
- Low mood or anxiety.
- More rarely, pain or bleeding in other areas such as the chest, which may cause shortness of breath.
Diagnosing endometriosis: the steps on the NHS
"Endometriosis is not always straightforward to diagnose, as there is no blood test, it does not always show up on scans, and symptoms overlap with other conditions," explains the RCOG's patient information leaflet on endometriosis. Here is the pathway set out in the recommendations of NICE guideline NG73, updated in November 2024:
Step 1 — Seeing your GP
Your GP takes a full history and offers an abdominal and pelvic (internal) examination. If you decline an internal examination or it is not suitable for you, an abdominal examination is offered instead. Initial treatment — painkillers or hormones — can start at the same time as the investigations: the two should run in parallel.
Step 2 — A transvaginal ultrasound scan
Since the 2024 update, a transvaginal scan should be offered to everyone with suspected endometriosis, even if the examination is normal, and organised by your GP practice. If a transvaginal scan is declined or unsuitable, a scan through the abdomen can be considered. A normal scan does not rule endometriosis out — and a referral may still be needed.
Step 3 — Referral and specialist imaging
You should be referred to a gynaecology service if initial treatment isn't working, isn't tolerated or isn't suitable, or if symptoms affect your daily life or keep coming back. Suspected deep endometriosis, an endometrioma (ovarian cyst) or endometriosis outside the pelvis calls for a specialist endometriosis service, where a specialist ultrasound or pelvic MRI can map the lesions.
Step 4 — Laparoscopy
A laparoscopy is keyhole surgery in which a camera is passed through a small cut in the tummy. NICE says it can be considered even if the scan or MRI was normal. During the procedure, a biopsy may confirm the diagnosis — though a negative result does not exclude endometriosis — and it may be possible to remove areas of endometriosis at the same time.
For complex cases, specialist endometriosis services (endometriosis centres) take over. According to NICE, these services should have access to gynaecologists with advanced laparoscopic skills, a colorectal surgeon and a urologist with an interest in endometriosis, a specialist nurse and a multidisciplinary pain management service with expertise in pelvic pain.
The types of endometriosis and its stages
Endometriosis UK describes four types of endometriosis — and it is possible to have more than one:
1. Peritoneal (superficial) endometriosis: found mainly on the pelvic peritoneum, the thin film that lines the inside of the pelvis. Small, superficial lesions can be missed on scans, yet they can be very painful.
2. Ovarian endometriosis (endometrioma): cysts on the ovaries, sometimes called "chocolate cysts". Because surgery can affect how many eggs the ovary holds, NICE asks surgeons to take your wish for fertility and your ovarian reserve into account when choosing how to treat them.
3. Deep endometriosis: lesions at a deeper level, in places such as the bladder, bowel and the tissue separating the vagina and the rectum. The most complex form — surgery for it often involves a multidisciplinary team.
4. Extra-pelvic endometriosis: endometriosis outside the pelvis, for example in the chest or in caesarean scars. It is rare.
The ASRM classification (American Society for Reproductive Medicine) divides the disease into four stages (I to IV) according to the extent of lesions. But stage and pain do not go hand in hand: someone at Stage I may suffer enormously, while someone at Stage IV may have few symptoms. That is why NICE tells clinicians to offer treatment according to the woman's symptoms, preferences and priorities, rather than the stage of the endometriosis.
Treating endometriosis: the options
There is currently no cure for endometriosis. As the NHS page on endometriosis puts it, treatment can help manage symptoms such as pain, and your doctor should talk you through the risks and possible side effects of each option. Care is tailored to your symptoms, your plans for a family and your preferences.
Medicines
- Painkillers: NICE suggests a short trial — around three months — of paracetamol or a non-steroidal anti-inflammatory drug (NSAID) such as ibuprofen, alone or combined. If that doesn't give adequate relief, other forms of pain management and a referral should be considered.
- Hormonal treatment: the combined pill or a progestogen, for example, should be offered to women with suspected, confirmed or recurrent endometriosis. It can reduce pain and has no permanent negative effect on later fertility. You can compare the methods in our complete guide to every contraceptive method and weigh up the hormonal coil in our copper vs hormonal IUD comparison.
- GnRH agonists: medicines that change the amount of hormones in your body. A three-month course may be considered before surgery for deep endometriosis involving the bowel, bladder or ureter.
Surgery
If other treatments are not working, or if endometriosis is affecting your fertility, you may be offered surgery, ideally by laparoscopy. The NHS lists the options: removing areas of endometriosis or ovarian cysts, removing part of the bladder or bowel if they are affected, or removing the womb (hysterectomy) or ovaries.
Surgery is not always a one-off: symptoms can return. Afterwards, NICE suggests considering hormonal treatment, such as the combined pill, to prolong the benefits of surgery.
Pain management and support beyond medicines
- Specialist pain services: NICE expects gynaecology services and endometriosis centres to have access to a multidisciplinary pain management service.
- Help with fatigue and long-term pain: the NHS lists advice on managing long-term pain and extreme tiredness among the support you might need.
- Mental health support: offered if you have low mood or anxiety, alongside physical treatment.
Endometriosis and fertility: what the evidence says
Endometriosis does not mean infertility. The RCOG leaflet puts it plainly: "While many women with endometriosis will be able to conceive naturally, for some endometriosis means it can take longer or be more difficult to get pregnant."
What we know:
- Between 30% and 50% of women with infertility have endometriosis, according to Endometriosis UK — which does not mean that most women with endometriosis are infertile.
- For endometriosis that does not involve the bowel, bladder or ureter, removing or destroying the lesions and freeing adhesions improves the chance of a spontaneous pregnancy (NICE).
- Surgery on endometriomas also improves the chance of spontaneous pregnancy, but it has to take the possible impact on ovarian reserve into account.
What you can do:
- If you are having difficulty getting pregnant, ask for a referral to a fertility specialist — the NHS lists it among the support available.
- Endometriosis-related subfertility should be managed by a multidisciplinary team with input from a fertility specialist, including assisted reproduction such as IVF where appropriate.
- Hormonal treatment on its own does not improve spontaneous pregnancy rates, so NICE says it should not be offered to women who are trying to conceive.
Living with endometriosis day to day
Day to day, endometriosis has to be managed on three fronts that treatment alone does not cover: work, intimate life and mental health.
At work
Under the Equality Act 2010, you are disabled if you have a physical or mental impairment that has a substantial and long-term negative effect on your ability to do normal daily activities — "long-term" meaning 12 months or more, as the GOV.UK guide to the definition of disability explains, with special rules for recurring or fluctuating conditions. Endometriosis can meet that definition. Employers must make sure workers with disabilities or health conditions are not substantially disadvantaged when doing their jobs — GOV.UK's guide to reasonable adjustments for workers with disabilities or health conditions gives a phased return to work with flexible hours or part-time working among the examples. Note that the Equality Act 2010 does not apply to Northern Ireland.
Intimate life
Deep pain during or after sex is one of the core symptoms of endometriosis, and it can put real strain on a relationship. Talking with your partner helps — so does raising it with a clinician, since NICE asks them to assess psychosexual as well as physical needs. If the pain has dulled your desire, our guide to low libido in women, its causes and solutions may help you see things more clearly.
Chronic pain and mental health
Living with unresolved chronic pain has a real psychological cost: anxiety, low mood, a sense of isolation. The years of waiting, the feeling of not being believed and the uncertainty about fertility all add to it. Getting psychological support — through your GP or NHS Talking Therapies, which can help with coping with a long-term condition such as chronic pain — is not a luxury. It is part of comprehensive care.
Endometriosis: how loved ones can really help
What helps someone with endometriosis:
- Believing her about her pain, without minimising or comparing.
- Learning about the condition (reading this guide is already a good start).
- Adjusting shared plans during painful episodes without making her negotiate or justify herself.
- Going with her to appointments if she would like the company.
- Avoiding comments about her treatment choices ("have you tried something more natural?").
- Not comparing ("my colleague has it and she never misses work").
What doesn't help (or makes things worse):
- "You'll be fine" — maybe, but it does nothing for the pain right now.
- "Have you tried cutting out gluten?" — unsolicited advice is rarely welcome.
- "Is it always this bad?" — every cycle is different, and the question adds pressure.
- Implying she is exaggerating or "using" her condition.
Endometriosis in the UK: charities, services and your rights at work
Charities and patient organisations:
- Endometriosis UK: the national charity, with a helpline (0808 808 2227), a web chat, an online community and local support groups.
- The Endometriosis Foundation: an online community and the option to speak to a nurse, both signposted by the NHS.
- Fertility Network UK: listed by the RCOG among the organisations that can help if endometriosis affects your fertility.
NHS and clinical resources:
- NICE guideline NG73, Endometriosis: diagnosis and management, freely available online.
- The BSGE's database of accredited endometriosis centres.
- The RCOG's patient information leaflet on endometriosis.
Your rights and money:
If endometriosis has a substantial and long-term effect on your daily life, the Equality Act 2010 protects you at work in England, Scotland and Wales, including the right to reasonable adjustments. If you need extra help to stay in work, you can apply for Access to Work, and the Disability Employment Adviser at your local Jobcentre Plus can advise on adjustments.
Frequently asked questions
Can endometriosis go away on its own?
There is currently no cure, and treatment aims to manage symptoms. But there is a reassuring point: according to the NHS, symptoms of endometriosis usually stop after the menopause — although it's possible to have symptoms after it. Until then, the right treatment can make a real difference to daily life.
Can you have endometriosis without painful periods?
Yes — and this is one of the most misleading aspects of the condition. Some people mainly have pelvic pain at other times of the month, cyclical bowel or urinary symptoms, extreme tiredness or difficulty getting pregnant. Others have very few symptoms at all. Because stage and pain do not match, extensive endometriosis can cause little pain, and vice versa.
Does the contraceptive pill hide endometriosis?
Hormonal contraception is itself one of the treatments NICE recommends, and it can reduce pain. However, by easing symptoms, it can delay recognition of the problem until you stop taking it — often when planning a pregnancy. That is why some women only discover their endometriosis after coming off the pill. If you are stopping, our timeline of what happens to your body after stopping the pill will help you tell a normal return of your cycle from a symptom that deserves a GP appointment.
Can diet improve endometriosis?
So far, the evidence is thin. NICE advises that the available evidence does not support supplements or Chinese herbal medicines for treating endometriosis, and no diet has been shown to replace medical treatment. A varied diet is good for your health in general — but a strict exclusion diet without a diagnosed intolerance is more likely to complicate your life than to treat the disease.
Can endometriosis continue after the menopause?
It is uncommon but possible: the NHS notes that symptoms usually stop after the menopause, although some people still have them. If a hysterectomy with removal of the ovaries is being considered, your clinician should discuss the possible benefits and risks of hormone replacement therapy (HRT) afterwards — so do mention your history of endometriosis whenever HRT comes up.
My GP says my pain is normal. What should I do?
Ask for a second opinion, without guilt. Under NICE guidance, you should be referred to a gynaecology service if initial treatment isn't working or tolerated, if your symptoms affect your daily activities, or if they persist or keep coming back. Take your pain diary along — it makes the conversation much more concrete. Endometriosis UK's helpline (0808 808 2227) is there for support too.
What is the impact of endometriosis on mental health?
It is real. Endometriosis can have a significant psychological and social impact, and the NHS lists low mood and anxiety among its symptoms. Years of pain, of not being believed and of uncertainty about fertility take their toll. Psychological support — through your GP, NHS Talking Therapies, a charity helpline or private counselling — should be part of your care, not an afterthought.
Sources
- NICE — Endometriosis: diagnosis and management (NG73), recommendations
- NHS — Endometriosis
- RCOG — Endometriosis patient information leaflet
- Endometriosis UK — Report on diagnosis times (March 2024)
- Endometriosis UK — Endometriosis facts and figures
- GOV.UK — Definition of disability under the Equality Act 2010
- GOV.UK — Reasonable adjustments for workers with disabilities or health conditions
- World Health Organization — Endometriosis fact sheet
- BSGE — Endometriosis centres