AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Background

Dysmenorrhea refers to the syndrome of painful menstruation. Primary dysmenorrhea occurs in the absence of pelvic pathology, whereas secondary dysmenorrhea results from identifiable organic diseases, most typically endometriosis, uterine fibroids, uterine adenomyosis, or chronic pelvic inflammatory disease. The prevalence of dysmenorrhea is estimated to be between 45 and 95% among reproductive-aged women. Although not life threatening, dysmenorrhea can be debilitating and psychologically taxing for many women and is one of the leading causes of absenteeism from work and school.

Pathophysiology

Historical attitudes toward menstrual pain were often dismissive. Pain was often attributed to women's emotional or psychological states, misconceptions about sex, and unhealthy maternal relations. Research has now established concrete physiologic explanations for dysmenorrhea, which discredit these prior theories.

Primary dysmenorrhea usually begins within the first 6-12 months after menarche once a regular ovulatory cycle has been established. During menstruation, sloughing endometrial cells release prostaglandins, which cause uterine ischemia through myometrial contraction and vasoconstriction. Elevated levels of prostaglandins have been measured in the menstrual fluid of women with severe dysmenorrhea. These levels are especially high during the first 2 days of menstruation. Vasopressin may also play a similar role.

Secondary dysmenorrhea may present at any time after menarche, but most commonly arises when a woman is in her 20s or 30s, after years of normal, relatively painless cycles. Elevated prostaglandins may also play a role in secondary dysmenorrhea, but, by definition, concomitant pelvic pathology must also be present. Common causes include endometriosis, leiomyomata (fibroids), adenomyosis, endometrial polyps, chronic pelvic inflammatory disease, and IUD use.

Frequency

United States

The prevalence of dysmenorrhea is estimated at 45-90%. This wide range can be explained by an assumed underreporting of symptoms. Many women self-medicate at home and never seek medical attention for their pain. As mentioned above, dysmenorrhea is responsible for significant absenteeism from work and school; 13-51% of women have been absent at least once, and 5-14% are repeatedly absent.

International

One longitudinal study from Sweden reported dysmenorrhea in 90% of women younger than 19 years and in 67% of women aged 24 years (French, 2005).

Mortality/Morbidity

Dysmenorrhea itself is not life threatening, but it can have a profoundly negative impact on a woman's day-to-day life. In addition to missing work or school, she may be unable to participate in sports or other activities, compounding the emotional distress brought on by the pain.

Race

No significant difference is apparent in the prevalence of dysmenorrhea among different populations.

Sex

Despite prevailing trends toward equality in the sexes, men are not yet known to experience dysmenorrhea.

Age

See Frequency above.

CLINICAL

Section 3 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

History

Primary dysmenorrhea may be distinguished from secondary dysmenorrhea by means of a thorough history. Pertinent information includes age at menarche, abnormal vaginal bleeding or discharge, dyspareunia, and obstetric history.

• Primary dysmenorrhea
• • Onset within 6-12 months after menarche
  • Lower abdominal/pelvic pain begins with onset of menses and lasts 8-72 hours
  • Low back pain
  • Medial/anterior thigh pain
  • Headache
  • Diarrhea
  • Nausea/vomiting
• Secondary dysmenorrhea
• • Onset in 20s or 30s, after relatively painless menstrual cycles in the past
  • Infertility
  • Heavy menstrual flow or irregular bleeding
  • Dyspareunia
  • Vaginal discharge
  • Lower abdominal or pelvic pain during times other than menses
  • Pain unrelieved by nonsteroidal anti-inflammatory drugs (NSAIDs)

Physical

A complete physical examination should be performed. For younger adolescents who have never been sexually active, a careful abdominal examination is appropriate. In older adolescents or those known to be sexually active, a pelvic examination is crucial. Pelvic ultrasonography should be considered in women who are suspected to have secondary dysmenorrhea.

• Primary dysmenorrhea
• • May have lower abdominal tenderness
  • May have uterine tenderness or normal pelvic examination (Cervical stenosis may contribute to retrograde menstrual flow.)
• Secondary dysmenorrhea
• • Palpable uterine mass or masses
  • Cervical motion tenderness
  • Adnexal tenderness or palpable mass or masses
  • Vaginal or cervical discharge
  • Visible vaginal pathology (mucosal tears, masses, prolapse)
  • Normal abdominal and pelvic examinations do not rule out pathology. Ultrasonography or other imaging modalities may be warranted if suspicion of secondary dysmenorrhea is high.

Causes

Risk factors

• Primary dysmenorrhea
• • Early age at menarche ( <12 y)
  • Nulliparity
  • Heavy or prolonged menstrual flow
  • Smoking
  • Positive family history
  • Obesity
• Secondary dysmenorrhea
• • Endometriosis
  • Adenomyosis
  • Leiomyomata (fibroids)
  • Intrauterine device
  • Pelvic inflammatory disease
  • Endometrial carcinoma
  • Ovarian cysts
  • Congenital pelvic malformations
  • Cervical stenosis

DIFFERENTIALS

Section 4 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Other Problems to be Considered

Ovarian neoplasm
Peritonitis
Pregnancy
Urinary tract infections
Uterine neoplasm
Endometriosis
Adenomyosis

WORKUP

Section 5 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Lab Studies

• The diagnosis of dysmenorrhea is generally clinical.
• Laboratory studies may be indicated to elucidate the cause of secondary dysmenorrhea.
• • Complete blood count (with differential), for evidence of infection or neoplastic process
  • Urinalysis, to exclude urinary tract infection
  • Quantitative human chorionic gonadotropin level, to exclude ectopic pregnancy
  • Gonococcal/chlamydial cervical swabs, to exclude STDs/PID
  • Stool guaiac, to rule out GI bleeding
  • Erythrocyte sedimentation rate (ESR), for subacute salpingitis

Imaging Studies

• In cases of well-established primary dysmenorrhea, imaging studies are of little value.
• If pelvic pathology is suspected, abdominal and/or transvaginal ultrasonography is an inexpensive and effective modality. Ultrasonography is relatively noninvasive, can easily be performed in the ED, and reveals most relevant pelvic pathology.
• MRI has limited ability to diagnose endometriosis.

Procedures

• Further investigation outside the ED might include hysterosalpingoscopy or laparoscopy. The latter is indicated when initial interventions fail to relieve symptoms.

TREATMENT

Section 6 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Prehospital Care

Many women never seek medical attention for dysmenorrhea. Self-medication with analgesics and NSAIDs as well as direct application of heat are common effective strategies.

Emergency Department Care

As always, ED evaluation should begin with the ABCs and should consider serious diagnoses such as hemorrhagic shock and sepsis. A patient whose history and clinical presentation clearly suggest primary dysmenorrhea may be treated symptomatically and provided with appropriate follow-up. A patient whose presentation is less clear, or whose vital signs and/or physical examination are abnormal, deserves a more thorough workup, including full laboratory studies, pelvic ultrasonography, and potentially an OB/GYN consultation.

Consultations

Patients with pelvic pain do not routinely need consultation with a gynecologist in the emergency department, though they should be directed to follow-up as an outpatient. Exceptions include certain infectious entities such as abscesses as well as neoplastic processes.

MEDICATION

Section 7 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Treatment of dysmenorrhea is aimed at providing symptomatic relief as well as inhibiting the underlying processes that cause symptoms.

NSAIDs reduce prostaglandin production via cyclooxygenase inhibition and are used as first-line therapy for dysmenorrhea. If taken early enough and in sufficient quantity, they are extremely successful in alleviating menstrual pain. Approximately two thirds of women achieve pain relief with NSAIDs. In the ED setting, patients who do not respond to NSAIDs may require treatment with narcotics for pain control. Patients whose symptoms are not relieved by NSAIDs are very likely to have underlying pelvic pathology such as endometriosis.

COX-2 specific inhibitors have also proven effective in relieving menstrual pain. Their selectivity reduces the GI symptoms caused by inhibition of the COX-1 receptor. However, recent clinical trials have raised into question their cardiovascular safety profiles. As a result, some of these agents are no longer available.

Simple analgesics, such as aspirin and acetaminophen, may also be useful, especially when NSAIDs are contraindicated.

Oral contraceptives, which block monthly ovulation and may decrease menstrual flow, may also relieve symptoms. In one clinical trial, 65% of women reported pain relief from oral contraceptives (Proctor, 2006).

Certain dietary supplements may be effective, though their effectiveness has only been demonstrated in small clinical trials. Thiamine, pyridoxine, magnesium, and fish oil are examples (Proctor, 2006).

Drug Category: Nonsteroidal anti-inflammatory agents

These drugs are highly effective in treating dysmenorrhea, especially when they are started before the onset of menses and continued through day 2. They are readily available, relatively inexpensive, and have a low side effect profile when used cautiously and in those who have no contraindications.

Drug Name	Naproxen (Anaprox, Naprelan, Naprosyn, Aleve)
Description	For relief of mild to moderate pain; inhibits inflammatory reactions and pain by decreasing activity of cyclooxygenase, which results in decrease of prostaglandin synthesis. Cost is approximately $3.00/d compared with $0.14/d for generic ibuprofen.
Adult Dose	500 mg PO followed by 250 mg q6-8h; not to exceed 1.25 g/d
Pediatric Dose	Not established
Contraindications	Documented hypersensitivity; peptic ulcer disease; recent GI bleeding or perforation; renal insufficiency
Interactions	Coadministration with aspirin increases risk of inducing serious NSAID-related adverse effects; probenecid may increase concentrations and, possibly, toxicity of NSAIDs; may decrease effect of hydralazine, captopril, and beta-blockers; may decrease diuretic effects of furosemide and thiazides; may increase PT when taking anticoagulants (instruct patients to watch for signs of bleeding); may increase risk of methotrexate toxicity; phenytoin levels may be increased when administered concurrently
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Category D in third trimester of pregnancy; acute renal insufficiency, interstitial nephritis, hyperkalemia, hyponatremia, and renal papillary necrosis may occur; patients with preexisting renal disease or compromised renal perfusion risk acute renal failure; leukopenia occurs rarely, is transient, and usually returns to normal during therapy; persistent leukopenia, granulocytopenia, or thrombocytopenia warrants further evaluation and may require discontinuation of drug

Drug Name	Diclofenac (Cataflam)
Description	Designated chemically as 2-[(2,6-dichlorophenyl) amino] benzene acetic acid, monosodium salt, with an empirical formula of C14 H10 Cl2 NO2 NA. One of a series of phenylacetic acids that has demonstrated anti-inflammatory and analgesic properties in pharmacologic studies. Believed to inhibit the enzyme cyclooxygenase, which is essential in prostaglandin biosynthesis. Can cause hepatotoxicity; hence, liver enzymes should be monitored in first 8 weeks of treatment. Rapidly absorbed; metabolism occurs in liver by demethylation, deacetylation, and glucuronide conjugation. Delayed-release, enteric-coated form is diclofenac sodium, and immediate-release form is diclofenac potassium. Has relatively low risk for bleeding GI ulcers.
Adult Dose	25 mg PO bid/tid If well tolerated, increase by 25 or 50 mg at weekly intervals until satisfactory response is obtained or total daily dose of 150-200 mg PO is reached Higher doses generally do not increase effectiveness
Pediatric Dose	<12 years: Not established >12 years: Administer as in adults
Contraindications	Documented hypersensitivity; do not administer into CNS or give to patients with peptic ulcer disease, recent GI bleeding or perforation, renal insufficiency, and those at high risk of bleeding
Interactions	Coadministration with aspirin increases risk of inducing serious NSAID-related adverse effects; probenecid may increase concentrations and, possibly, toxicity of NSAIDs; may decrease effect of hydralazine, captopril, and beta-blockers; may decrease diuretic effects of furosemide and thiazides; may increase PT when taking anticoagulants (instruct patients to watch for signs of bleeding) may increase risk of methotrexate toxicity; phenytoin levels may be increased when administered concurrently
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Acute renal insufficiency, hyperkalemia, hyponatremia, interstitial nephritis, and renal papillary necrosis may occur; increases risk of acute renal failure in patients with preexisting renal disease or compromised renal perfusion; low WBC counts occur rarely, and usually return to normal in ongoing therapy; discontinuation of therapy may be necessary if leukopenia, granulocytopenia, or thrombocytopenia persists

Drug Name	Hydrocodone and acetaminophen (Vicodin, Lorcet-HD, Lortab)
Description	Drug combination indicated for moderate to severe pain.
Adult Dose	1-2 tab or cap PO q4-6h prn pain
Pediatric Dose	<12 years: Not established >12 years: 750 mg acetaminophen PO q4h; not to exceed 10 mg hydrocodone bitartrate per dose or 5 doses/24 h
Contraindications	Documented hypersensitivity; high altitude cerebral edema (HACE) or elevated intracranial pressure (ICP)
Interactions	Coadministration with phenothiazines may decrease analgesic effects; toxicity increases with CNS depressants or tricyclic antidepressants
Pregnancy	D - Unsafe in pregnancy
Precautions	Tab contain metabisulfite, which may cause hypersensitivity; caution in patients dependent on opiates since this substitution may result in acute opiate-withdrawal symptoms; caution in severe renal or hepatic dysfunction

FOLLOW-UP

Section 8 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Further Outpatient Care

• Patients with both primary and secondary dysmenorrhea should be provided with appropriate GYN follow-up. If they do not have regular medical care, an appointment with a primary medical doctor is also indicated. Patients whose symptoms are not relieved by NSAIDs are very likely to have underlying pelvic pathology such as endometriosis.

In/Out Patient Meds

• NSAIDs
• Analgesics

Deterrence/Prevention

• Smoking cessation should be encouraged.
• One randomized controlled trial showed a significant association between a low-fat vegetarian diet and a reduction in symptoms (Proctor, 2006).
• Physical exercise may also improve menstrual pain by improving blood flow and releasing endorphins.
• One randomized controlled trial showed that acupuncture also improved symptoms.

Complications

• If a diagnosis of secondary dysmenorrhea is missed, the underlying pathology may lead to increased morbidity, including sterility.
• Social isolation and/or depression

Prognosis

• The prognosis for primary dysmenorrhea is excellent with the use of NSAIDs.
• The prognosis for secondary dysmenorrhea varies depending on the underlying disease process.

Patient Education

• Dysmenorrhea: Painful Menstrual Periods
• Health Information, National Institutes of Health (NIH)

MISCELLANEOUS

Section 9 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Medical/Legal Pitfalls

• Incorrect diagnosis of primary dysmenorrhea/failure to diagnose serious underlying GYN pathology

ACKNOWLEDGMENTS

Section 10 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

The authors and editors of eMedicine gratefully acknowledge the contributions of previous author, Thomas Steele, DO† , to the development and writing of this article.

REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

• Andersch B, Milsom I. An epidemiologic study of young women with dysmenorrhea. Am J Obstet Gynecol. Nov 15 1982;144(6):655-60. [Medline].
• Berkley KJ. A life of pelvic pain. Physiol Behav. Oct 15 2005;86(3):272-80. [Medline].
• Durain D. Primary dysmenorrhea: assessment and management update. J Midwifery Womens Health. Nov-Dec 2004;49(6):520-8. [Medline].
• French L. Dysmenorrhea. Am Fam Physician. Jan 15 2005;71(2):285-91. [Medline].
• Latthe P, Mignini L, Gray R, et al. Factors predisposing women to chronic pelvic pain: systematic review. BMJ. Apr 1 2006;332(7544):749-55. [Medline].
• Proctor M, Farquhar C. Diagnosis and management of dysmenorrhoea. BMJ. May 13 2006;332(7550):1134-8. [Medline].

Article Last Updated: Nov 13, 2006