Endometriosis | Kōpū whakatupu pūtautau

Endometriosis (kōpū whakatupu pūtautau) is a common condition where tissue similar to endometrial tissue, which should only be found in the uterus (womb), also grows outside the uterus, such as on ovaries or the bowel. This generally causes pain and can cause other symptoms.

Key points about endometriosis

  1. Endometriosis affects up to 1 in 10 women and teenage girls.
  2. The cause of endometriosis is not fully known, but it often runs in families.
  3. The most common symptom of endometriosis is pelvic pain.
  4. Endometriosis can be very difficult to diagnose. The only sure way is by a surgical procedure called a laparoscopy.
  5. Treatment usually involves a combination of surgical, medical and self-management options.

What is endometriosis?

Endometrial tissue is sensitive to hormone levels and changes as these fluctuate. In a normal menstrual cycle, hormones from your ovaries make the endometrial tissue grow. After a few weeks, if you do not get pregnant, these hormone levels decrease causing the endometrial tissue to shed and you have a period. In endometriosis, endometrial-like tissue, which has grown outside your uterus, also responds to the same hormones – the tissue grows and then bleeds. This can be very painful and is why, if you have endometriosis, you usually have pain leading up to and during your period. 

Image credit: Vega asensio Wikimedia Commons

Over time, the cycles of growth and break-down of the endometriosis tissue causes scarring, cysts and other damage on places such as the pelvic lining (peritoneum), ovaries and bowel. This is why early diagnosis and treatment are important to reduce possible complications, such as fertility problems.

In rare cases, endometriosis can be found in other parts of your body.

 (Merck, US, 2020)

What causes endometriosis?

The cause of endometriosis is not fully known. It is thought it may be caused by a number of different factors and there may be a genetic component, so it may run in families. Research continues in this area.

What are the symptoms of endometriosis?

The most common symptom of endometriosis is pelvic pain. The pain is usually linked to your menstrual cycle. However, women with endometriosis may also experience pain at other times during the month.

For many women, the pain can be so severe it can prevent them from carrying out their normal daily activities. Some women with endometriosis may have no symptoms at all, which is less common.   

Symptoms of endometriosis include:

  • pain with periods (dysmenorrhoea)
  • bowel problems, such as bloating, diarrhoea, constipation, pain with bowel movements (dyschezia), painful wind
  • painful intercourse (dyspareunia)
  • sub-fertility or infertility
  • tiredness and low energy
  • pain in other places such as the lower back or leg
  • pain at other times, eg, with ovulation
  • premenstrual syndrome (PMS)
  • abnormal menstrual bleeding
  • pain before or with urination, recurrent urinary tract infections (UTIs), or interstitial cystitis (inflammation of the bladder causing painful urination).

Looking at this factsheet on the symptoms of endometriosis may help you decide whether your symptoms are likely to be due to endometriosis. This visual tool may help you to put together the symptoms you are experiencing and help to focus any discussions you have with health professionals. If you experience symptoms regularly talk to your doctor – you may need a referral to a gynaecologist.

How is endometriosis diagnosed?

Endometriosis can be very difficult to diagnose. The only sure way to diagnose endometriosis is by a surgical procedure called a laparoscopy. This is usually a straight-forward operation but like any operation, there are some risks. That is why tests will usually be done before surgery, such as: 

  • Physical examination and history taking: you will be asked about your periods and the pain associated with them. It can be useful to keep a diary of details about your periods or use an app to track them. 
  • Blood tests: there is no blood test which can diagnose endometriosis, but blood tests may be required to help rule out other conditions or before surgery.
  • Ultrasound: the endometriosis tissue cannot be seen by ultrasound, but if there are endometriosis cysts then these can be seen. The results of scarring can also sometimes be seen by ultrasound.
  • Laparoscopy: this procedure involves a small incision being made just below your tummy button. A lighted telescopic instrument called a laparoscope is inserted through the incision and the pelvic organs can be seen. This is done under a general anaesthetic by a specialist gynaecologist. During this procedure, tissue can be removed for testing, and endometriosis lesions can be removed, or organs that have become stuck together or to the pelvic wall can be separated.

Grades of endometriosis

Endometriosis is often classified as mild, moderate or severe, though different grading systems may be used.




Appears as small patches or surface lesions scattered around the pelvic cavity.


Appears as larger widespread disease starting to infiltrate tissue and often found on the ovaries, uterosacral ligaments and pouch of Douglas.


Affects most of the pelvic organs, often with distortion of the anatomy and adhesions.

Grading like this can have limitations, eg, the extent of endometriosis is not generally related to the symptoms experienced.

How is endometriosis treated?

As the cause of endometriosis is still not understood, no particular treatment will provide a permanent cure. The most suitable treatment for you will depend on many factors, including:

  • your age
  • whether you plan to have children
  • the severity of the symptoms
  • the extent of the endometriosis
  • your preference.

Treatment usually involves a combination of surgical, medical and self-management options. To find the right treatment for your particular situation, a referral to a gynaecologist who has a special understanding and skill in treating pelvic pain and endometriosis is recommended.

All treatment options should be explored so that a long-term plan can be arranged. Unfortunately, endometriosis is known to recur, and repeat treatment procedures are sometimes necessary.

Read more about treatment options.


Healthy eating and keeping active are key ways to manage endometriosis. Some people with endometriosis have a sensitised bowel and find avoiding certain foods helpful. Others find complementary therapies helpful, especially in managing pain.

Learn more

About endometriosis Endometriosis, NZ
About endometriosis Insight Endometriosis, NZ
Endometriosis The Royal Australian and NZ Society of Obstetricians & Gynaecologists
Recent research about endometriosis Endometriosis, NZ
Endometriosis Mayo Clinic, US
Endometriosis – diagnosis and management BPAC, NZ
Endometriosis and pelvic pain Pelvic Pain Foundation of Australia
Raising Awareness tool for endometriosis (RATE) The Royal Australian and NZ Society of Obstetricians & Gynaecologists
Endometriosis factsheets Insight Endometriosis, NZ


  1. The pharmacological management of endometriosis BPAC, 2013
  2. Chronic pelvic pain in women BPAC, 2015
  3. Hogg S, Vyas S. Endometriosis update. Obstet Gynaecol Reprod Med. 2017; 28(3):61-69.
  4. Dunselman GAJ, Vermeulen N, Becker C, Calhaz-Jorge C, D’Hooghe T, De Bie B, et al. ESHRE guideline: Management of women with endometriosis Hum Reprod. 2014;29(3):400–12.
  5. Auckland Regional HealthPathway 
Credits: Health Navigator Editorial Team. Reviewed By: Dr Zoe LaHood, Senior House Officer, Hutt Valley DHB, NZ Last reviewed: 25 Nov 2022