Endometriosis is a condition where tissue that is similar to the lining of the uterus or womb (endometrial tissue) grows elsewhere in the body. This usually occurs in the fallopian tubes or ovaries. This tissue behaves in the same way as normal endometrial tissue, meaning that every month it thickens, breaks down and bleeds. Unlike normal endometrial tissue, which is released from the body during a woman’s monthly menstrual period, tissue that is located elsewhere in the body has nowhere to go. Thus, it accumulates; causing swelling, followed by inflammation and pain. Scar tissue can cause irritation to the surrounding tissue and, if the ovaries are affected, blood can accumulate forming cysts called endometriomas.
Whilst 20-25% of patients with endometriosis are asymptomatic, of the 75-80% who are affected, the symptoms can be quite debilitating. Symptoms may include chronic pelvic pain, which occurs around the same time as menstruation, bowel and bladder problems and heavy periods. One of the main complications of the condition is problems with fertility, which affects up to 40% of women with endometriosis. In severe cases, the endometrial tissue will have to be surgically removed.
Endometriosis is a long-term condition that typically affects women in their 30s and 40s. The chronic nature of the symptoms means that patients will often experience concurrent depression and fatigue. It is also sometimes confused with irritable bowel syndrome, as the symptoms can be very similar.
The exact cause of endometriosis remains unknown. It is thought to be due to a combination of genetic susceptibility, hormonal imbalance and immune system dysfunction. Retrograde menstruation is also believed to play a role. Retrograde menstruation occurs when menstrual blood containing endometrial cells enters the fallopian tube instead of leaving the body. This is known as the transplantation theory and can also occur when the endometrial cells travel elsewhere in the body via the bloodstream.
Living with endometriosis can be challenging, both emotionally and physically. If you are affected and it is having an impact on your quality of life, the first step is to seek medical advice and support.
Bulletti, C, et al. “Endometriosis and Infertility.” Journal of Assisted Reproduction and Genetics, vol. 27, no. 8, Aug. 2010, pp. 441–447., doi:10.1007/s10815-010-9436-1.
Koninckx, P R, et al. “Pathogenesis of Endometriosis: the Genetic/Epigenetic Theory.” Fertility and Sterility, vol. 111, no. 2, Feb. 2019, pp. 327–340., doi:10.1016/j.fertnstert.2018.10.013.
Overview: Endometriosis. NHS, www.nhs.uk/conditions/endometriosis/. Page last reviewed: 18/01/2019.
Understanding Endrometriosis. Endometriosis UK, www.endometriosis-uk.org/understanding-endometriosis.
Endometriosis. Mayo Clinic, 24 July 2018, www.mayoclinic.org/diseases-conditions/endometriosis/symptoms-causes/syc-20354656.