Pain during periods can be due to dysmenorrhea or endometriosis. Differentiation of both type of pain is difficult and only expert gynecologist can diagnose properly. Dysmenorrhea is due to increased levels of prostaglandins which are produced to cause contraction in the uterus to push the blood and endometrial lining out. This causes pain. Endometriosis is the growth of endometrial tissue out side uterus but inside pelvis. As this tissue is part of endometrium, it also bleeds during periods causing pain. So, you should visit a doctor for differential diagnosis and treatment.
