What Causes Endometriosis?

Endometriosis occurs when the cells that normally line the uterus (endometrium) enter the pelvis or bloodstream and attach to other organs. These endometrial implants can grow and damage the structures they are attached to, leading to organ dysfunction. These patches can be located in the peritoneum, ovaries, around the fallopian tubes, in the gastrointestinal tract (12-37%), around the bladder (20%), and (less commonly) in the vagina. When they are located in the fallopian tube, they can penetrate and obstruct the fallopian tube and lead to infertility.

Endometrioma – Also called “chocolate cysts,” endometrioma is a cyst filled with thick, old, dark brown blood, and is located inside the ovaries. Endometrioma occurs with advanced stage endometriosis, which leads to infertility and pelvic pain. Larger endometriomas require surgical resection with laparoscopy.

Endometriosis- Endometriosis is a disorder of an impaired immune system, which allows the endometrial implants to invade and proliferate the body. Biopsies of endometriosis contain high levels of macrophages, which contain cytokines and prostaglandins. These factors produce inflammation and damage to the surrounding tissues.

Family History – Women who have a mother or sister with endometriosis are ten times more likely to have the disease, indicating a likely genetic link. It is defined by the presence of endometrial glands and stroma outside the uterus. The most popular theory of why endometriosis occurs is retrograde menstruation with an altered immune response.