What Causes Endometriosis?
One theory suggests that endometrial tissue is distributed from the uterus to other parts of the body through the lymph or blood systems.
A genetic theory suggests that certain families have predisposing factors for the disease.
Surgical transplantation has also been cited in many cases where endometriosis is found in abdominal scars, although it has also been found in such scars when accidental implantation seems unlikely.
Another theory suggests that remnants of tissue from when the woman was an embryo may later develop into endo or that some adult tissues retain the ability they had in the embryo stage to transform under certain circumstances.
The retrograde menstruation theory (trans-tubal migration theory) suggests that during menstruation some of the menstrual tissue backs up through the fallopian tubes, implants in the abdomen, and grows. Some experts believe that all women experience some menstrual tissue backup and that an immune system problem or a hormonal problem allows this tissue to grow in the women who develop endometriosis.