Cyclic pain associated with ovulatory cycles without demonstrable lesions affecting reproductive structures.

The pain is thought to result from uterine contractions and ischemia, probably mediated by prostaglandins produced in secretory endometrium; therefore, primary dysmenorrhea is almost always associated with ovulatory cycles. Contributing factors may include the passage of tissue through the cervix, a narrow cervical os, malposition of the uterus, lack of exercise, and anxiety about menses. This common disorder usually starts during adolescence and tends to decrease with age and after pregnancy.

Symptoms and Signs
Low abdominal pain is usually crampy or colicky but may be a dull constant ache and radiate to the lower back or legs. The pain may start before or with menses, tends to peak after 24 h, and usually subsides after 2 days. Sometimes endometrial casts (membranous dysmenorrhea) or clots are expelled. Headache, nausea, constipation or diarrhea, and urinary frequency are common; vomiting occurs occasionally. PMS symptoms may persist during part or all of the menses.

Treatment
A woman should be assured that her reproductive organs are normal. Many women do not need drugs, but for women with substantially bothersome symptoms, the most effective drugs are prostaglandin synthetase inhibitors (eg, ibuprofen, naproxen, mefenamic acid). A drug may be more effective if started 24 to 48 h before and continued 1 or 2 days after menses begins. If pain continues to interfere with normal activity, suppression of ovulation with low-dose estrogen-progesterone oral contraceptives is advisable. Antiemetics may be used. Adequate rest and sleep and regular exercise may help.