Dysmenorrhea is painful menstruation and is the most common of all gynecologic complaints, and the leading cause of absenteeism of women from work, school, and other activities. In addition to identifiable pathological causes, number of constitutional factors may lower pain threshold thus appearing as worsening dysmenorrhoea. Common factors include anemia, an increase in obesity, chronic illness, overwork, stress in general, diabetes, and poor nutrition. Two forms of dysmenorrhea can be identified:

• Primary dysmenorrhea not related to any definable pelvic lesion. This usually begins with the first ovulatory cycles beginning in most cases before the age of 20. Primary dysmenorrhea is associated with nausea in 50% of patients, vomiting in 25% of patients and stool frequency in 35% of patients. The pain is low and crampy recurring in waves that probably correlate with uterine contractions. The pain usually occurs a few hours before bleeding, comes to a peak intensity within a few hours, and dissipates within 1-2 days. It generally occurs over the midline, and is relieved by the onset of good menstrual flow.
• Secondary dysmenorrhea related to the presence of pelvic lesions secondary to organic pelvic disease such as endometriosis, salpingitis and PID (pelvic inflammatory disease), post surgical adhesions, etc. Secondary dysmenorrhea begins up to a few days before menstruation and lasts several days after the onset of flow. Often it is lateralized to one side, and it does not characteristically peak and diminish as clearly or quickly as primary dysmenorrhea. It's onset is later in life in women who have not had primary dysmenorrhea, however it can be superimposed onto a pre-existing case of primary dysmenorrhea. The I.U.D. may cause such pain problems.