The question many women have is why do these growths cause endometriosis pain in the first place?

The answer, for the most part, lies in the woman's monthly menstrual 子宮內膜增生 cycle because most women experience the most severe pain just before and during their period. The reason for this is that the endometrial cells living outside a woman's uterus respond to her monthly hormonal cycle the same as the endometrium lining the uterus.

The endometrial cells become engorged with blood and other nutritive tissue but as a woman's period begins they too begin to shed, but in the case of endometriosis the blood and tissue remains inside the abdominal cavity. Endometrial tissues also release chemicals that can be irritating to abdominal organs and in some cases cause pain.

This process repeats itself every month causing the endometrial growths to grow into nodules on the abdominal organs. They can also turn into fluid filled sacs known as cysts when implanted on the ovaries. These cysts can break, causing pain and fluid release into the lower pelvic region. These nodules, cysts and chemicals can also produce scarring on the pelvic organs and in severe cases the scar tissue can bind the organs together. The abdominal organs are free floating and when they become attached to one another with scar tissue there is real discomfort and pain, particularly with any body movement.