The actual cause of endometriosis is unknown. There are many studies that suggest this disease can be caused by the following:-
- Retrograde menstruation. It has been suggested that this can occur when menstrual blood and tissue from the uterus enters the peritoneal cavity by flowing through the fallopian tubes. This can cause endometrial cells to grow outside of the uterus.
- A poor immune system. The reasoning behind this is unclear but endometriosis is an inflammatory disease. Some studies have suggested this may contribute to an imbalanced immune response.
- A genetic link with mothers/sisters/aunts having the disease.
None of these theories have been confirmed and the cause of endometriosis still remains unknown.