Overview
Endometriosis is a chronic, painful condition in which tissue similar to the lining inside the uterus (endometrium) grows outside the uterus, commonly on the ovaries, fallopian tubes, and the tissue lining the pelvis. This misplaced tissue acts like normal endometrial tissue — thickening, breaking down, and bleeding with each menstrual cycle — but cannot exit the body, causing inflammation, scar tissue, and adhesions. Endometriosis can significantly impact fertility and quality of life.
Causes and risk factors
The following factors are associated with the development of Endometriosis:
- Exact cause unknown
- Retrograde menstruation — menstrual blood flows backward
- Immune system dysfunction failing to destroy misplaced tissue
- Genetic predisposition — runs in families
- Surgical scar implantation after C-section or hysterectomy
- Embryonic cell transformation
- Lymphatic or vascular spread of endometrial cells
- Hormonal factors — oestrogen drives growth
Signs and symptoms
Common signs and symptoms of Endometriosis include:
- Painful periods (dysmenorrhoea) — often severe
- Pelvic pain between periods
- Pain during or after sexual intercourse
- Pain with bowel movements or urination
- Heavy menstrual bleeding or bleeding between periods
- Infertility
- Fatigue
- Bloating and nausea
- Diarrhoea or constipation during periods
Diagnosis
Endometriosis is typically diagnosed through a combination of medical history, physical examination, and appropriate investigations such as blood tests, imaging, or specialist review, depending on the specific condition and presentation. Your doctor will consider all relevant symptoms and risk factors before making a diagnosis.
Treatment options
Treatment approaches for Endometriosis may include:
- Pain management: NSAIDs, paracetamol
- Hormonal therapies: combined pill, progesterone-only pill, Mirena IUS
- GnRH agonists (e.g. leuprorelin) to reduce oestrogen temporarily
- Laparoscopic surgery to remove endometrial deposits
- Hysterectomy in severe cases where family is complete
- Fertility treatment if trying to conceive
- Multidisciplinary pain management approach
- Psychological support
Prevention
No known prevention. Early diagnosis and treatment are important. Hormonal contraceptives may reduce risk or slow progression.
Complications
If left untreated or poorly managed, Endometriosis can lead to complications including:
Infertility (affects 40–50% of those with endometriosis), ovarian cysts (endometriomas), bowel and bladder problems, and psychological impact.
Sources and references: This article is written in accordance with NHS UK, WHO, and Mayo Clinic clinical guidelines. It is reviewed for accuracy by the SymptomSense content team. ICD-10 code: N80. Last reviewed June 2026.