Endometriosis is a chronic and painful disease
Understanding endometriosis can be difficult. Learn more about the inner workings of the disease and why it hurts.
Endometriosis occurs when tissue that acts a lot like the lining of your uterus—called endometrium—starts growing outside of your uterus, where it doesn't belong.
These out-of-place growths, called lesions or implants, can cause severe pain and inflammation throughout the month.