What causes endometriosis?
The exact cause of endometriosis is not fully known. However, several conditions may provide possible explanations:
Retrograde menstruation - During your period, menstrual blood containing endometrial cells can flow backwards through the fallopian tubes and into your abdomen instead of leaving your body as a period. The endometrial cells can then stick to the surfaces of organs in your abdomen and grow. If your body is unable to clear this tissue naturally, it becomes a problem.
Immune system disorder - An immune deficiency may prevent your body from recognising displaced endometrial tissue growing outside the womb as “foreign” and so will not attack and destroy it as normal.
Endometrial cell transport - If endometrial cells get into the bloodstream or lymphatic system, they can potentially be transported all around the body. This may cause rarer cases of endometriosis that occur outside the pelvic area.
Genetics - Endometriosis may be inherited. Although it can affect any ethnicity, it is more common in Asian women and less common in women of African-Caribbean origin.
Surgical scar implantation - After abdominal surgery, such as a hysterectomy or C-section, endometrial cells can attach to the incision area.
Endometriosis usually develops several years after the start of menstruation, commonly in women aged between 25 and 40. However, it can also develop in postmenopausal women and women who have had a hysterectomy.