Primary Dysmenorrhea: Primary dysmenorrhea is painful menstrual cramps without any pelvic pathology. Increased production of prostaglandins in the uterine lining cause uterine contractions; as a result, the endometrium sheds. When the level of prostaglandins decreases, menstrual cramps decreases.
Secondary Dysmenorrhea: Secondary dysmenorrhea is caused by disorders of pelvic organs, adenomyosis, endometriosis, congenital anomalies, or fibroids. This pain gradually increases over time.