Dysmenorrhea, or painful menstruation, is experienced by approximately 50% of woman; it is severe or disabling in 10%, causing a loss of workdays and poor performance at school. Dysmenorrhea is caused by the production of prostaglandins during menstruation. Prostaglandins enhance uterine contractions, causing pelvic pain. Primary dysmenorrhea is caused by normal uterine muscle contractions and affects more than half of menstruating women.

Secondary dysmenorrhea is menstrual-related pain that is caused by abnormal medical conditions, such as endometriosis. The pain begins with the onset of menstrual flow and lasts 2-3 days. It is characterized by crampy, lower abdominal pain that radiates to the back region or inner thigh region. Nausea, headache, or fatigue may accompany the pain.

Key points for TCM diagnosis
(1) The main clinical symptom is lower abdominal pain during menstruation. It usually occurs 1-2 days before menstruation or after menstruation.

(2) The manifestations are paroxysmal spasmodic pain or distending pain in the lower abdomen; the pain may radiate to the lumbosacral region, anus, vagina or medial side of the leg. In serious cases there are pale complexion, cold sweating, cold hands and feet, nausea and vomiting, diarrhea or even syncope. In a few cases, dysmenorrhea may be accompanied by symptoms of irritation sign of bladder, such as frequent urination and urgent urination. The duration of pain lasts from 2-3 days.

(3) Basic temperature detection usually indicates ovulation menstrual cycle. Gynecological examination can be done to see whether there are abnormal changes in the shape, location and texture of the uterus and whether there is thickening change of the appendage as well as whether there is mass and tenderness.

(4) Ultrasonic test, pelvic pneumography and peritoneoscopy are made to decide whether dysmenorrhea is functional or organic. Prostaglandin test of menses can suggest whether there is abnormal increase of prostaglandin

(5) Measures should be taken to differentiate dysmenorrhea from abdominal pain caused by extrauterine pregnancy, rupture of corpus luteum, torsion of ovarian cyst, acute pelvitis, acute cystitis, urinary stones, appendicitis, colitis and acute gastroenteritis, etc.