Endometriosis is a common condition where tissue similar to the lining of your womb (endometrium) starts to grow elsewhere and attaches to other organs, such as your ovaries and fallopian tubes. It is usually limited to organs in your pelvic area and lower tummy.

By Wallace Health I Medically reviewed by Adrian Roberts.
Page last reviewed: October 2018 I Next review due: October 2023

What is endometriosis?

Endometriosis is a chronic (long-term) condition.

The most common symptom is period pain and pelvic cramps, which can be severe enough to disrupt everyday activities. Left untreated, endometriosis can lead to fertility problems as the build-up of endometrium tissue can cause ovarian cysts, which interfere with egg production. Endometrium tissue can also block your fallopian tubes.

Endometriosis usually starts between the ages of 25 to 50 but sometimes begins in the teenage years. It isn’t known exactly how many women have endometriosis as it doesn’t always cause symptoms or symptoms are mild — this means it is often not diagnosed. However, endometriosis is estimated to affect one in 10 women of child-bearing age. The earlier it’s diagnosed and treated the less likely you are to have chronic pain or damage to your fallopian tubes and long-term infertility.

Endometriosis can affect any woman but you may be at greater risk if you have a close relative with endometriosis eg your mother, sister or aunt. Your risk of endometriosis is reduced if you take the combined oral contraceptive pill and this protective effect may last for up to a year after you stop taking the pill. Endometriosis is very rare in post-menopausal women. This is because the female hormone oestrogen is needed to develop endometriosis and oestrogen levels drop after menopause. 

Endometriosis symptoms are usually mild to moderate and can be managed with medication. However, you may need surgical treatments for moderate to severe endometriosis. It usually stops altogether by the time you reach menopause.

How to tell if you have endometriosis

  • Patches of overgrown endometrium can be as small as the size of a pinhead but can grow to form large clumps. Usually, bigger patches cause worse symptoms. 

    Some women have no or mild symptoms, while others have moderate or severe symptoms. Signs of endometriosis are usually worse around the time of your period. Symptoms include:

    • Difficulty getting pregnant — the reason is not always clear but it can sometimes be due to endometrium blocking the passage of an egg in the fallopian tube
    • Heavy periods (menorrhagia) — you may have to use two types of sanitary products at the same time (eg pads and tampons) and/or you may bleed through to your clothes and bedsheets
    • Pain during sex — the pain is felt deep inside you and may last for several hours after sex
    • Pain when urinating or passing a stool during your period
    • Painful periods (dysmenorrhoea) — this can prevent you from carrying out your normal activities; it usually starts a few days before your period and lasts the duration of your period; normal period pain does not last as long and is not as severe
    • Pelvic pain and tenderness ie pain in your lower back and tummy — this can be constant but is usually worse a few days before and during your period

    During your period, you may also: 

    You may also bleed from your vagina in between your periods. In very rare cases, patches of endometrium may grow beyond the pelvic area and lower tummy and cause pain in these areas during your period. 

    With more severe endometriosis you might also have:

    • Chronic (long-term) pelvic pain
    • Ovary pain during ovulation
    • Rectal bleeding or blood in your urine

    Endometriosis can have a big impact on your quality of life and lead to depression.

    Endometriosis can be graded according to how many patches of endometrium you have and how deep they go. There are four stages:

    • Stage I (minimal) — a few superficial patches
    • Stage II (mild) — more patches that are deeper
    • Stage III (moderate) — many deep patches, small cysts on one or both ovaries and fibrous bands that loosely connect organs (filmy adhesions)
    • Stage IV (severe) — many deep patches, large cysts on one or both ovaries and many adhesions

Talk to your doctor if you’re concerned about symptoms

You can book an appointment with a Spire private GP today.

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Diagnosis and tests for endometriosis

See your GP if you have endometriosis symptoms, particularly if they are affecting your quality of life. You may want to write down your symptoms and any questions you have before your appointment. 

It can be difficult to diagnose endometriosis as symptoms vary and other conditions have similar symptoms. To help diagnose endometriosis your GP will ask about your symptoms. They may also carry out:

If symptoms are severe, you may be referred to a gynaecologist (a consultant specialising in the female reproductive system).

Endometriosis is often diagnosed by a procedure called a laparoscopy, which uses a thin, telescope-like tube to look inside your pelvic area for any patches of endometrium. This tube is passed into your tummy via a small cut.

An MRI scan is sometimes used to diagnose ovarian cysts and more severe endometriosis.

If you have endometriosis, your doctor will recommend treatments.

Causes of endometriosis

The exact cause of endometriosis is unknown. However, genetics, the immune system, hormones and environmental factors are thought to play a role.

You’re at a higher risk of endometriosis if:

  • You are of Asian descent — there is some limited evidence that ethnicity affects the risk of developing endometriosis
  • You have a condition affecting your immune system — endometrium cells are believed to spread to other areas via blood and lymphatic vessels, which are part of your immune system
  • You have never given birth
  • You have retrograde menstruation — when some of your menstrual blood, which contains endometrial cells, flows backwards into your fallopian tubes and pelvis instead of flowing out of your body 
  • Your mother, sister or aunt has endometriosis
  • You started your periods early or you’re late going through the menopause

Patches of endometrium are sticky and can join organs together by forming adhesions eg your bladder and bowel can become adhered to your womb. Large patches of endometrium can also form cysts that bleed when you have a period. If the cysts fill with dark blood they are called chocolate cysts. 

Q & A

Endometriosis: symptoms, diagnosis and treatment

Mr Mohan Kumar, Consultant Gynaecologist, explains that if you're experiencing pelvic pain, painful periods, and pain during and after intercourse, you might have endometriosis.

Common treatments for endometriosis

Endometriosis can't be cured and can be difficult to treat. You may find it useful to attend a support group to help you cope with the challenges of living with endometriosis. 

There are treatments to reduce your symptoms so you can continue with your normal activities. The longer endometriosis is left untreated, the greater your risk of fertility problems, so the sooner you get treatment, the better. 

Your gynaecologist will discuss your treatment options, as well as the risks and benefits. The effectiveness of treatments in reducing symptoms varies between women and different treatments have different side effects. 

When deciding on the most appropriate treatment, your gynaecologist will consider: 

  • How you feel about surgery
  • If you want to become pregnant — some treatments prevent you from getting pregnant
  • Whether you have tried any other treatments
  • Your age
  • Your main symptoms eg pain or difficulty getting pregnant

You may not need treatment if your symptoms are mild, you have no fertility problems or if you are reaching menopause. Your symptoms may improve without any treatment. 

Your treatment will therefore depend on the severity of your endometriosis. Most endometriosis is mild or moderate and can be helped with pain medication and/or hormone therapies.

Pain medication

Over-the-counter painkillers (eg paracetamol) and anti-inflammatory drugs (eg ibuprofen) can help manage your pain and most often do not cause side effects. If after taking pain medication for a few months, you are still in pain, see your GP. 

If you can't tolerate anti-inflammatory drugs, you can try codeine or codeine combined with paracetamol for stronger pain relief. A common side effect of taking codeine is constipation

Hormone therapies

Hormone therapies limit or stop oestrogen production — this female sex hormone is what causes the endometrium to grow and shed each month. Hormone therapies can reduce the build-up of endometrium tissue but do not affect adhesions or improve fertility. It may take several months of hormone treatment before your symptoms improve. 

The two main hormone therapies for endometriosis are the combined oral contraceptive pill and progestogens. They are equally effective but have different side effects. Both reduce your chances of getting pregnant but do not permanently affect your fertility. They are not all contraceptives. 

The combined oral contraceptive pill

Also known as the pill, it contains two hormones: oestrogen and progestogen. It can relieve mild endometriosis symptoms and be used in the long term. It works by stopping eggs being released (ovulation), which makes your periods lighter and less painful. 

Your doctor may recommend taking three packs of the pill one after the other without a break to reduce your bleeding and improve your symptoms. The pill has side effects but by trying different brands, you may find one that suits you better.


Progestogens are synthetic hormones that mimic the natural hormone progesterone. They slow the growth of endometrium tissue. Side effects include: 

  • Bloating
  • Irregular bleeding
  • Mood changes
  • Weight gain

Progestogens for treating endometriosis include:

  • A contraceptive implant
  • A contraceptive injection
  • An intrauterine device (IUD) — this is placed in your womb and releases progestogen
  • Progestogen tablets eg norethisterone — these are not contraceptives
  • The progestogen-only pill (POP)

Your doctor may recommend starting these treatments before your diagnosis is confirmed. If you need contraception too, they may suggest using the levonorgestrel-releasing intrauterine system (LNG-IUS).

If pain medication and hormone therapy are not effective, you may need a standard surgical procedure to remove or destroy patches of endometrium. 

Before surgery, your doctor may recommend a three-month course of gonadotrophin-releasing hormone (GnRH) analogues. These are synthetic hormones that reduce oestrogen production and cause temporary menopause. They reduce the amount of endometrium tissue. They are not a contraceptive, so you should still use contraception while taking these hormones. 

Types of surgery used to treat endometriosis include: 


This is the most common technique and is used to destroy patches of endometrium and ovarian cysts. It is sometimes also used to diagnose endometriosis — if used for diagnosis, your surgeon may ask for your consent before the procedure to destroy or remove any patches of endometrium tissue that they may find. 

The procedure involves passing a thin telescope-like tube with a light and a camera at the end into your tummy via a small cut. This sends images of the inside of your tummy and pelvis to a computer screen. Other fine instruments are inserted through small cuts in your tummy. These instruments use a beam of special gas, a laser, an electric current or heat to remove or destroy patches of endometrium.

Laparoscopy is performed under general anaesthetic. It can reduce your symptoms and in some cases, improve fertility. However, your endometriosis symptoms may return, particularly if some endometrium patches are left behind. 


This is a less common procedure as it is a major surgery and is only appropriate if you do not want to have children. This procedure removes your womb, which has a big impact on your body. It can’t be reversed. It is unlikely but not impossible for endometriosis symptoms to return after a hysterectomy. 

Before surgery, your doctor will talk to you about hormone replacement therapy (HRT) — you may need this after having a hysterectomy. There are different types of HRT and it isn't clear which is best for women with endometriosis. Oestrogen-only HRT may cause endometriosis symptoms to return if any patches of endometrium are left behind after surgery. 

Taking HRT will not significantly increase your risk of breast cancer until you reach the average age for menopause.

Tubal surgery 

This is used to repair damaged fallopian tubes.

Following an endometriosis diet

Eating large amounts of certain foods can increase your risk of endometriosis — this includes: 

  • High trans-fat foods — trans fats are found in fried, processed and fast foods
  • Red meat 

There is some evidence that certain foods can worsen endometriosis symptoms — this includes:  

  • High-FODMAP foods — FODMAP stands for fermentable oligo-, di-, monosaccharides and polyols, which are a type of carbohydrate; a research study showed people with endometriosis and irritable bowel syndrome (IBS) who followed a low-FODMAP diet reported an improvement in their symptoms
  • Foods containing gluten — a research study of 207 women with endometriosis who eliminated gluten from their diet showed three-quarters reported reduced pain 

Foods that may improve your endometriosis symptoms include: 

  • Foods rich in antioxidants, such as colourful fruits and vegetables (beetroot, berries, oranges and spinach), and dark chocolate
  • Foods rich in essential fatty acids, such as certain fish (herring, salmon, sardines and trout), chia seeds, flax seeds and walnuts
  • Fibrous foods, such as fruits, legumes, vegetables and whole grains
  • Iron-rich foods, such as beans, broccoli, dark leafy greens, fortified grains, nuts and seeds

How does endometriosis progress?

If endometriosis is not treated:

  • Four in 10 cases get worse
  • Three in 10 cases get better on their own 
  • Three in 10 cases stay the same

Endometriosis is not cancerous. 

Further problems caused by endometriosis

Fertility problems

This is the main complication caused by endometriosis. You may not be able to get pregnant or you may find it difficult to get pregnant. The cause isn't always clear but may be due to damage endometriosis causes to your fallopian tubes or ovaries. You may still be able to get pregnant eventually without treatment.

Surgery to remove patches of endometrium can help but does not guarantee that you will be able to get pregnant. Infertility treatments, such as in vitro fertilisation (IVF), may help although IVF is less successful in women with moderate to severe endometriosis.

Adhesions and ovarian cysts

Adhesions are sticky patches of endometrium that join organs together. 

Ovarian cysts are fluid-filled cysts in your ovaries that can become large and painful.

Adhesions and ovarian cysts are more likely if your endometriosis occurs in or near your ovaries.

Bladder and bowel problems

If endometriosis spreads to your bladder or bowel it can cause problems with these organs. This can be difficult to treat and you may need major surgery. Endometriosis surgery on the bladder may involve removing part of the bladder.

Complications from endometriosis surgery 

Common complications after surgery, which can be effectively treated, include: 

  • Bruising around the surgical wound
  • Infection at the site of surgery
  • Minor bleeding

Less common complications that are more serious include:

  • Blood clots — this includes: 
    • Deep vein thrombosis — a blood clot in a vein, deep in your leg
    • Pulmonary embolism — a blood clot in your lungs
  • Organ damage during surgery eg a hole accidentally being made into your bladder, bowel or womb
  • Severe bleeding in your tummy

Living with endometriosis

It can be difficult to live with endometriosis, both physically and emotionally. You can get support from your doctor and may also benefit from contacting a support group.

Frequently asked questions

How serious is endometriosis?

Endometriosis is not life-threatening but it can cause considerable pain that reduces your quality of life. In moderate and severe cases, the challenges of living with endometriosis can cause depression. It can also cause fertility problems.

What happens if endometriosis is left untreated?

In most cases, endometriosis will stay the same or get better, even without treatment. However, in four out of 10 cases, it will get worse, causing increasing pain and a higher risk of fertility problems.

What is the main cause of endometriosis?

The exact cause of endometriosis is not yet known. However, there are several risk factors, such as having a close relative (a mother, sister or aunt) who has the condition, starting your periods early or being late to go through the menopause. Other risk factors include conditions affecting your immune system, retrograde menstruation and never having given birth.

Where is endometriosis pain felt?

Endometriosis pain is usually felt in the pelvic area and lower back. However, in some cases patches of endometrium grow elsewhere, outside of these areas — this can cause pain in other parts of your body, especially during your period.

Can you have a baby with endometriosis?

You can get pregnant if you have endometriosis. It is estimated that seven in 10 women with mild to moderate endometriosis will get pregnant without needing fertility treatment. However, women with moderate or severe endometriosis are more likely to have fertility problems.

What stage of endometriosis do I have?

Endometriosis is graded according to four stages depending on the number of endometrium patches you have and their depth. In stage I, you have a few, superficial patches. In stage II, there are more patches, which are deeper. In stage III, you have many deep patches, as well as adhesions and ovarian cysts. In stage IV, you also have many deep patches as well as more adhesions and larger ovarian cysts.

Will a hysterectomy cure endometriosis?

In most cases, endometriosis does not return in women who have had a hysterectomy. However, it is not impossible eg if patches of endometrium remain elsewhere in the body.

Will endometriosis kill me?

No, endometriosis is not life-threatening — it is not cancer.

Does endometriosis cause smell?

Endometriosis does not cause unpleasant smelling discharge from your vagina. It can however cause heavy bleeding that soaks through your sanitary products and clothes.

Does endometriosis make you tired?

Yes, endometriosis can make you feel tired. This may be caused by heavy bleeding and/or by having to deal with constant pain in your lower back and pelvic area during your period.

Does endometriosis cause weight gain?

There isn’t strong evidence to suggest that endometriosis causes weight gain. However, taking progestogen, a treatment for endometriosis, can cause weight gain in some women. You may also gain weight if pain caused by your endometriosis prevents you from exercising and staying active.

Does endometriosis worsen with age?

Endometriosis usually gets better after menopause when your oestrogen levels drop as oestrogen is needed for the endometrium to grow.

Can endometriosis cause birth defects?

No, endometriosis does not cause birth defects.