Endometriosis: symptoms, diagnosis and treatment options

What is endometriosis?

In endometriosis, patches of tissue resembling the endometrium (the inner lining of the womb) grow outside the womb – most often on the ovaries, fallopian tubes, the lining of the pelvis and the ligaments supporting the womb, and sometimes on the bowel or bladder. These patches respond to the hormones of the menstrual cycle, causing inflammation, pain and scar tissue (adhesions) that can stick organs together.

The World Health Organization estimates that endometriosis affects roughly 10% of women and girls of reproductive age worldwide. It is a chronic condition: it cannot usually be cured once and for all, but in most cases symptoms can be well controlled.

There are several forms:

• superficial peritoneal endometriosis – patches on the lining of the pelvis;
• endometriomas (“chocolate cysts”) on the ovaries;
• deep endometriosis – growing into nearby organs such as the bowel or bladder.

A related condition, adenomyosis, occurs when similar tissue grows into the muscle wall of the womb; the two often occur together.

Endometriosis symptoms

Symptoms vary widely and do not always match how much endometriosis is present – small patches can be very painful, while extensive disease may cause few symptoms. Common symptoms include:

• painful periods that stop you going to work or school and do not respond well to ordinary painkillers;
• pelvic pain at other times of the month;
• pain during or after sex;
• pain when opening your bowels or passing urine, especially during a period;
• bloating, nausea, constipation or diarrhoea around your period;
• heavy bleeding and ongoing fatigue;
• difficulty getting pregnant – endometriosis is a common cause of infertility.

Similar symptoms can be caused by fibroids, pelvic infection or bowel conditions such as Crohn’s disease and ulcerative colitis, so a specialist assessment is important.

Causes and risk factors

The exact cause is unknown. The most widely accepted theory is retrograde menstruation, where some menstrual blood containing endometrial cells flows backwards through the fallopian tubes into the pelvis. Because this happens to most women but only some develop endometriosis, the immune system, genes and hormones are also thought to play a part.

The risk is higher if you have:

• a mother, sister or daughter with endometriosis;
• started periods early or have short cycles;
• heavy and long periods;
• a condition that blocks the normal flow of menstrual blood.

Endometriosis is not a sexually transmitted infection, is not contagious and is not caused by anything a woman has done.

How endometriosis is diagnosed

Current European guidance from ESHRE emphasises that treatment can start on the basis of typical symptoms and examination, without waiting for surgery to confirm the diagnosis. Assessment usually involves:

• a detailed history – the type of pain, its link to your cycle and its impact on daily life; keeping a symptom diary helps;
• a pelvic examination – which may reveal tender nodules or a fixed womb;
• a transvaginal ultrasound scan – reliably shows endometriomas and, in experienced hands, deep endometriosis;
• MRI – if deep endometriosis is suspected or before planning surgery (see MRI and CT scans);
• laparoscopy – keyhole surgery with a camera, allowing biopsies and removal of patches; it is now mainly recommended when scans are normal but treatment has not helped, or when surgery is planned anyway.

The blood marker CA-125 may be raised but cannot reliably confirm or rule out endometriosis (read more about tumour markers).

Treatment options

The aims are to relieve pain, protect fertility and slow progression. Treatment is individual.

Pain relief

Non-steroidal anti-inflammatory painkillers often help with period pain. Chronic pain may need a broader approach, including pelvic floor physiotherapy and psychological support.

Hormonal treatment

Hormonal medicines suppress the cycle and reduce the activity of endometriosis. Options include the combined contraceptive pill, progestogens (tablets or a hormone-releasing intrauterine system) and GnRH agonists or antagonists, usually with “add-back” therapy to protect bone. Your gynaecologist will choose based on symptoms, side effects and pregnancy plans. Hormonal treatment works while it is taken and does not improve fertility.

Surgery

Laparoscopic surgery removes or destroys endometriosis patches, removes endometriomas and frees adhesions. Deep endometriosis involving the bowel or bladder should be treated by a multidisciplinary team in a specialist centre. With endometriomas, surgeons take care to preserve healthy ovarian tissue, because surgery can reduce ovarian reserve. For women with severe symptoms who do not want more children, hysterectomy is sometimes discussed, but it does not guarantee that pain will go away.

Endometriosis and fertility

Many women with endometriosis conceive naturally. The condition can, however, damage the tubes and ovaries and change the environment in the pelvis. Depending on your age, ovarian reserve and the state of your tubes, your doctor may suggest trying naturally for a while, keyhole surgery, intrauterine insemination or IVF. Before surgery for endometriomas, egg freezing is sometimes discussed. Do not try to get pregnant as a way to “treat” the pain without talking to a specialist first.

When to see a doctor

See your GP or a gynaecologist if:

• period pain makes you miss work or school or does not settle with usual painkillers;
• you have pelvic pain between periods or pain during sex;
• you have pain passing urine or opening your bowels that is linked to your cycle;
• you have been trying to conceive for over a year (or six months if you are over 35).

Seek urgent help for sudden severe abdominal pain with vomiting, fever or fainting, which could indicate a ruptured or twisted ovarian cyst. If you feel your pain has been dismissed, you are entitled to ask for a second medical opinion.

Treatment abroad and in Türkiye

For deep endometriosis, the experience of the surgical team matters a great deal. Some patients from Europe choose laparoscopic or robotic surgery at large accredited hospitals in Istanbul, where gynaecologists with a special interest in endometriosis work alongside general surgeons and urologists. Check the hospital accreditation, the surgeon’s experience specifically with endometriosis, the written plan (extent of surgery, risks, length of stay) and how follow-up at home will be organised. Organisers such as New City Clinic coordinate the hospital, doctor, hotel, transfers and an interpreter. If fertility treatment is also planned, see IVF in Turkey.