Endometriosis: What It Is, What Causes It, and How to Treat It
Endometriosis is a common and often painful condition that affects about 10% of women of reproductive age. It occurs when tissue like the lining of the uterus (endometrium) grows outside the uterus, such as on the ovaries, fallopian tubes, bowel, bladder, or pelvic wall. This tissue responds to hormonal changes and bleeds during the menstrual cycle, but unlike normal endometrium, it has no way to exit the body. This can cause inflammation, scarring, adhesions, and cysts in the affected areas.
The main symptom of endometriosis is pelvic pain, which can vary from mild to severe and can interfere with daily activities and quality of life. The pain is usually worse during or before periods, but it can also occur at other times, such as during ovulation, intercourse, bowel movements, or urination. Other symptoms may include heavy or irregular bleeding, infertility, fatigue, bloating, nausea, or diarrhoea.
The exact cause of endometriosis is unknown, but several factors may contribute to its development, such as:
- Retrograde menstruation: This is when some of the menstrual blood flows back through the fallopian tubes and into the pelvic cavity instead of leaving the body. This blood may contain endometrial cells that implant and grow in other locations.
- Hormonal imbalance: This is when the levels of oestrogen and progesterone are abnormal or fluctuate excessively. These hormones regulate the growth and shedding of the endometrium. Too much oestrogen may stimulate the growth of endometrial-like tissue outside the uterus.
- Immune system problems: This is when the immune system fails to recognize and eliminate the endometrial-like tissue that grows outside the uterus. This may allow the tissue to persist and proliferate.
- Genetic factors: This is when a person inherits a gene or genes that increase their susceptibility to endometriosis. Endometriosis tends to run in families and affects certain ethnic groups more than others.
- Environmental factors: This is when a person is exposed to toxins or chemicals that may affect their hormonal balance or immune system. For example, some studies have suggested that dioxin, a pollutant found in some herbicides and industrial products, may be linked to endometriosis.
- The diagnosis of endometriosis can be challenging because its symptoms are often nonspecific or similar to other conditions. The gold standard for diagnosis is laparoscopy. Other tests that may help with diagnosis include pelvic examination, ultrasound, MRI, or blood tests.
The treatment of endometriosis depends on several factors, such as the severity of symptoms, the extent of disease, the age of the patient, and their desire for pregnancy. There is no cure for endometriosis, but its symptoms can be managed with medications or surgery in some cases. The main goals of treatment are to relieve pain, reduce inflammation, prevent progression, and restore fertility if desired.
The medications that are used for endometriosis include:
- Painkillers: These are drugs that help reduce pain and inflammation. They include nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen; opioids, such as codeine or morphine; or nerve blockers, such as gabapentin or pregabalin.
- Hormonal therapy: These are drugs that help suppress or regulate the hormonal changes that stimulate the growth of endometrial-like tissue. They include oral contraceptives, progestins, gonadotropin-releasing hormone (GnRH) agonists, aromatase inhibitors, or selective progesterone receptor modulators (SPRMs).
The surgeries that are used for endometriosis include:
- Laparoscopy: This minimally invasive procedure allows clinicians to remove or destroy the endometrial-like tissue using instruments inserted through small incisions in the abdomen. This can help reduce pain and improve fertility in some cases.
- Laparotomy: This more invasive procedure involves making a larger incision in the abdomen to access and remove larger areas of endometrial-like tissue. This may be necessary if laparoscopy is not feasible or effective.
- Hysterectomy: involving removal of the uterus and sometimes the ovaries and fallopian tubes as well. This can help eliminate pain and bleeding caused by endometriosis, but it also means that pregnancy is no longer possible.
Health care professionals who want to learn more about endometriosis and how to diagnose and treat it effectively can benefit from attending a gynae core skills course offered by Practitioner Development UK (PDUK). This course is designed to provide practitioners with the knowledge and skills to perform a comprehensive gynaecological assessment and manage common gynaecological problems. The course covers topics such as anatomy and physiology of the female reproductive system, history taking, common gynaecological conditions and their management, contraception and sexual health, menopause and hormone replacement therapy, and referral pathways and guidelines. The course is delivered virtually over one day and includes lectures, demonstrations, and case studies. The course is suitable for nurses, midwives, pharmacists, paramedics, and other health care professionals who want to expand their scope of practice and improve their gynaecological care.
In summary, endometriosis is a common and often painful condition that affects many women of reproductive age. It is caused by the growth of endometrial-like tissue outside the uterus, which responds to hormonal changes and bleeds during the menstrual cycle. It can cause symptoms such as pelvic pain, heavy or irregular bleeding, infertility, fatigue, bloating, nausea, or diarrhoea. It can be diagnosed by laparoscopy or other tests and treated by medications or surgery depending on the individual case. Health care professionals can enhance their knowledge and skills on endometriosis by attending a CPD SO accredited gynaecology core skills course offered by PDUK.
References
- World Health Organization (WHO) (2018). Endometriosis. [online] Available at: [1] [Accessed 11 Nov. 2022].
- Mayo Clinic (2020). Endometriosis - Symptoms and causes. [online] Available at: [2] [Accessed 11 Nov. 2022].
- Healthline (2019). Endometriosis: Causes, Complications, and Treatment. [online] Available at: [3] [Accessed 11 Nov. 2022].
- Practitioner Development UK (n.d.). A01 Gynae Core Skills: Face to Face. [online] Available at: [4] [Accessed 11 Nov. 2022].
Article information
Written by: Practitioner Development UK
Reviewed by: Dr Debra Sharu, Practitioner Development UK
Last reviewed and updated: 15 May 2026
Medical disclaimer: This article is for general educational information only and is not a substitute for professional medical advice, diagnosis or treatment. Endometriosis symptoms, investigation and treatment options can vary between individuals. Anyone experiencing persistent pelvic pain, heavy or irregular bleeding, pain during sex, bowel or bladder symptoms, fertility concerns, or symptoms that affect daily life should seek advice from an appropriately qualified healthcare professional.
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