Dysmenorrhea (or dysmenorrhoea), cramps or painful menstruation, involves menstrual periods that are accompanied by either sharp, intermittent pain or dull, aching pain, usually in the pelvis or lower abdomen.

Painful menstruation affects approximately 40% of menstruating women, and 10% are incapacitated for up to 3 days. Painful menstruation is the leading cause of lost time from school and work among women of childbearing age. This pain may precede menstruation by several days or may accompany it, and it usually subsides as menstruation tapers off.

Although some pain during menstruation is normal, excessive pain is not. Dysmenorrhea refers to menstrual pain severe enough to limit normal activities or require medication. It may coexist with excessively heavy blood loss (menorrhagia).

• Primary dysmenorrhea refers to menstrual pain that occurs in otherwise healthy women (Wright et al. 2003). This type of pain is not related to any specific problems with the uterus or other pelvic organs.
• Secondary dysmenorrhea is menstrual pain that is attributed to some underlying disease process or structural abnormality either within or outside the uterus (for example, pelvic inflammatory disease, fibroids, endometriosis, adhesions, adenomyosis, uterine displacement, or a retroverted uterus). Endometriosis is the most common cause of dysmenorrhea associated with a disease process and is frequently misdiagnosed.

The incidence of menstrual pain is greatest in women in their late teens and 20s, then declines with age. Some women experience increased menstrual pain in their late 30s and 40s as their endocrine systems prepare for menopause by decreasing hormone levels and thus fertility. It does not appear to be affected by childbearing. An estimated 10 percent to 15 percent of women experience monthly menstrual pain severe enough to prevent normal daily function at school, work, or home.

The majority of women will suffer this degree of disability at least once during their reproductive years. Increased risk is associated with younger age, and past medical history of any of the conditions associated with secondary dysmenorrhea.

Primary Dysmenorrhea

Pathophysiology

Primary dysmenorrhea occurs during regular ovulatory cycles. Women with primary dysmenorrhea have increased activity of the uterine muscle with increased contractility and increased frequency of contractions. Prostaglandins are released during menstruation due to destruction of the endometrial cells and the resultant release of their contents.

Release of prostaglandins and other inflammatory mediators in the uterus (womb) is thought to be a major factor in primary dysmenorrhea (Wright et al. 2003). Prostaglandin levels have been found to be much higher in women with severe menstrual pain than in women who experience mild or no menstrual pain. Drugs which inhibit the production of prostaglandins, such as the non-steroidal anti-inflammatories (NSAIDs) Naproxen, Ibuprofen and Mefenamic Acid, can provide relief for the discomfort and other associated symptoms of excessive prostaglandin release, such as nausea, vomiting, and headache.

Clinical Features

The cramping associated with dysmenorrhea usually begins a few hours before the start of bleeding and may continue for a few days. The pain is usually described as being in the lower abdomen, possibly radiating to the thighs and lower back. Other symptoms associated with primary dysmenorrhea are nausea and vomiting, fatigue, diarrhea, lower backache, and headache.

Treatment

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen, are very effective in the treatment of primary dysmenorrhea (Andreoli et al. 2004). As earlier stated, their effectiveness comes from their ability to inhibit prostaglandin synthesis. However, many NSAIDs can cause gastrointestinal upset as a side effect. Patients who cannot take NSAIDs may be prescribed a cyclo-oxygenase (COX) inhibitor. Oral contraceptives are also sometimes used since they reduce menstrual flow and inhibit ovulation.

Secondary Dysmenorrhea

Pathophysiology

The mechanisms causing the pain of secondary dysmenorrhea are varied and may or may not involve prostaglandins. Some causes of secondary dysmenorrhea are endometriosis, pelvic inflammation, fibroid tumors, adenomyosis, ovarian cysts, and pelvic congestions (Hacker et al. 2004). The presence of an IUD (intrauterine device) for contraception may also be a potential cause of menstrual pain, although they usually lead to pelvic pain only around the time of insertion. Some women also find that use of tampons exacerbates menstrual cramps and pain.

Clinical Features

The symptoms of secondary dysmenorrhea vary with the underlying cause, but generally the pain associated with secondary dysmenorrhea is not limited to the time around menses as with primary dysmenorrhea. Also, secondary dysmenorrhea is less related to the onset of bleeding in menstruation, is seen in older women, and is associated with other symptoms like infertility.

Treatment

The most effective treatment of secondary dysmenorrhea is the identification and treatment of the underlying cause of the pain, although the relief provided by NSAIDs is often helpful.

Related Problems

• Premenstrual syndrome (PMS)
• Stress and anxiety
• Pelvic inflammatory disease
• Adenomyosis
• History of sexual or physical abuse
• Fibroids
• Ovarian cysts
• Endometriosis

References

• Andreoli, Thomas E., Charles C. J. Carpenter, Robert C. Griggs, and Joseph Loscalzo. CECIL Essentials of Medicine, 6th ed. Saunders, 2004. ISBN 0-7216-0147-2
• Hacker, Neville F., J. George Moore, and Joseph C. Gambone. Essentials of Obstetrics and Gynecology, 4th ed. Elsevier Saunders, 2004. ISBN 0-7216-0179-0
• Wright, Jason and Solange Wyatt. The Washington Manual Obstetrics and Gynecology Survival Guide. Lippincott Williams and Wilkins, 2003. ISBN 0-7817-4363-X

External link

• NIH

Gynecology | Menstruation

Dysménorrhée | Dysmenorrea | 經痛