Dysmenorrhea (Greek term, meaning “painful menstruation”, is a medical condition of excessive menstrual pain during menstruation that interferes with daily activities (Fig. 1, []). It does not include the common situation of mild discomfort or pain during normal menstruation. The menstrual pain of dysmenorrhea is often described as menstrual cramps, also including sharp, throbbing, dull, burning, or shooting pain in the lower abdomen []. Dysmenorrhea often co-occur with other symptoms including breast tenderness, nausea, vomiting, diarrhea, constipation, headache, dizziness, disorientation, hypersensitivity to sound, light, smell and touch, fainting, and fatigue [2,].
Clinically, dysmenorrhea can be classified as primary or secondary. If a detailed gynecological clinical examination failed to find the significant abnormalities on pelvic organs, it is diagnosed as a primary dysmenorrhea, also known as functional dysmenorrhea. Secondary dysmenorrhea refers obvious genital diseases, such as endometriosis, pelvic inflammation, cancer and so on [].
Primary dysmenorrhea is more common in women 20-30 years of age. Then the incidence gradually decreases with age, while secondary dysmenorrhea gradually increased. The incidence of dysmenorrhea worldwide can be as wide as 16.8-81%. The different definitions and different survey methods make it difficult to obtain the true incidence of dysmenorrhea. Unless the symptoms affect the quality of life, women may not see a doctor on those discomforts []. In an investigation of 388 female Australian students in Grades 11 and 12, 53% of those girls with dysmenorrhea reported that it limited their activities [].
Dysmenorrhea can be caused by many factors. The following are the common ones []:
- Stenosis of uterine cervix is the mainly obstructions that are preventing outflow of menstruation, leading dysmenorrhea.
- Uterine hypoplasia may have uterine ischemia and hypoxia, leading dysmenorrhea.
- The abnormal position of the uterus (extreme tilted forwards or backwards, Fig. 2 []) can affect blood outflow, leading dysmenorrhea.
- Mental and neurological factors: Some women are over-sensitive to pain. Girl’s menarche, psychological stress may cause dysmenorrhea.
- Genetic factors: There is a certain relationship between mother and daughter on dysmenorrhea.
- Endocrine factors: Dysmenorrhea may be related to the elevated progesterone.
- The increased endometrial and menstrual blood prostaglandin plays a role in the contraction of the uterine muscle fibers and may cause dysmenorrhea.
- Excessive or abnormal contractions of the uterus lead to uterine ischemia and uterine muscle spasms, resulting in pain in menstruation.
- Gynecological diseases, such as endometriosis, pelvic inflammation, adenomyosis, hysteromyoma and intrauterine device can easily cause dysmenorrhea.
- Sedentary lifestyle, eating cold food, strenuous exercise during menstruation, invasion by the wind, cold and damp, stimulations by some industrial or chemical odor (gasoline, perfume), etc., may cause dysmenorrhea.
If the symptoms of primary dysmenorrhea are strong enough to disrupt the normal life and activities significantly, palliative medical therapy may be applied, including non-steroidal anti-inflammatory drugs, COX-2 inhibitor, hormonal contraceptives, estrogen and progesterone [2,7]. For the secondary dysmenorrhea, it is very important to cure the original diseases that cause the pain, rather than just the pain management temporarily.
1. Qi stagnation and blood stasis: Distending pain and tenderness in the lower abdomen one or two days prior to or during menstruation accompanied with fullness sensation in the chest, hypochondrium and breast, deep-purple blood with clots, relief of pain after discharge of clots, ecchymoses on the tongue edges, string-like pulse. Treatment by soothing the liver and regulating Qi, removing blood stasis and relieving pain with Ge Xia Zhu Yu Tang (膈下逐瘀汤) with addition: Dang Gui (当归), Chi Shao (赤芍), Liu Ji Nu (刘寄奴), Niu Qi (牛膝) 15g each，Chuan Qiong (川芎), Tao Ren (桃仁), Hong Hua (红花), Yan HuSuo (延胡索), Wu LingZhi (五灵脂), Wu Yao (乌药), Xiang Fu (香附) 12g each，Zhi Qiao (枳壳), Dan Pi (丹皮) 9g each，Gang Cao (甘草) 6g and Dan Sen (丹参)30g。
2. Stagnancy of Cold and Dampness: Distending pain in the lower abdomen several days prior to or during menstruation, which can be relieved by warmth, menstrual flow scanty in amount, dark in color and with clots, pale tongue with white and greasy fur, deep and tense pulse. Treatment by warming the channels and removing blood stasis, dispersing cold and eliminating wet with Shao Fu Zhu Yu Tang (少腹逐瘀汤) with addition: Xiao Hui Xiang (小茴香), Gang Jiang (干姜), Rou Gui (肉桂) 6g each，Yan Hu Suo (延胡索), Chuan Qiong (川芎), Cang Zhu (苍术) 9g each，Mo Yao (没药), Chi Shao (赤芍), Pu Huong (蒲黄), Wu Ling Zhi (五灵脂), Wu Yao (乌药), Wu Zhu Yu (吴茱萸) 12g each，Dang Gui (当归), Fu Ling (茯苓) 15g each。
3. Deficiency of Both Qi and Blood: Vague pain in the lower abdomen during or 1-2 days after menstruation which can be relieved by pressing, scanty menstruation with reddish and thin blood, accompanied with lack of vitality and asthenia, pale tongue with white and thin fur, thready and weak pulse. Treatment by replenishing Qi, nourishing blood and relieving pain with Shen Yu Tang (圣愈汤) with addition or subtraction: Ren Sen (人参), Dang Gui (当归), Shu Di (熟地), Ji Xue Ten (鸡血藤) 15g each，Huang Qi (黄芪) 30g，Chuan Qiong (川芎), Xiang Fu (香附), Yan HuSuo (延胡索), Zhi Gang Cao (炙甘草) 9g each，Bai Shao (白芍) 18g and Hong Hua (红花) 12g。
4. Liver and Kidney Deficiency: Pain in the lower abdomen during or 1-2 days after menstruation, sour and pain in lower back, thin menstrual flow, scanty in amount, dark in color, dizziness, tinnitus, hot flush, thready and weak pulse, thin and white or yellow tongue coating. Treatment by nurturing kidney, nourishing liver and relieving pain with Tiao Gan Tang (调肝汤) with addition: Dang Gui (当归), Shan Zhu Yu (山茱萸), E Jiao (阿胶), Shan Yao (山药), Xiang Fu (香附) 12g each，Bai Shao (白芍), Ba Ji Tian (巴戟天), Shu Di (熟地) 15g each，Gang Cao (甘草) 6g，Gou Qi Zi (枸杞子) 30g and Dan Pi (丹皮) 9g。
In addition, acupuncture, nutrient supplements (vitamin B3, vitamin C, rutin , fish oil, magnesium ), diet modifications (higher fiber, protein, less sweets and avoiding caffeine), keeping warm (including topical heat on the lower abdomen), proper exercise before menstruation and stress relief will help to release the pain of the primary dysmenorrhea .
 Dysmenorrhea position: http://www.alive.com/articles/view/18461/dysmenorrhea
 Latthe P et al: WHO systematic review of prevalence of chronic pelvic pain: neglected reproductive health morbidity ：BMC Public Health ，2006 ：6: 177
 Hillen TI et al: Primary dysmenorrhea in young Western Australian women: prevalence, impact, and knowledge of treatment. J Adolesc Health. 1999 Jul;25(1):40-5.
 Anteflexed retroflexed uterus: https://www.google.com/search?q=abnormal+position+of+the+uterus&rlz=1I7GGLD_en&source=lnms&tbm=isch&sa=X&ei=eLMcU7LRJIiF2QX8uoD4DQ&ved=0CAcQ_AUoAQ&biw=1536&bih=814#q=anteflexed+retroflexed+uterus&spell=1&tbm=isch&imgdii=_
 TCM treatment: http://wenku.baidu.com/view/747ba5360b4c2e3f57276361.html