Dysmenorrhea is uterine pain around the time of menses. Pain may occur with menses or precede menses by 1 to 3 days. Pain tends to peak 24 hours after onset of menses and subside after 2 to 3 days. It is often crampy or a dull constant ache but may be sharp or throbbing; it may radiate to the back or legs.
Headache, nausea, constipation or diarrhea, lower back pain, and urinary frequency are common; vomiting occurs occasionally.
Sometimes dysmenorrhea is accompanied by symptoms of premenstrual syndrome or heavy menstrual bleeding and passage of blood clots.
In about 5 to 15% of women with primary dysmenorrhea, cramps are severe enough to interfere with daily activities and may result in absence from school or work.
Pain sensitivity with dysmenorrhea may increase susceptibility to other chronic pain conditions in later life.
Etiology of Dysmenorrhea
Dysmenorrhea can be
Primary (more common)
Secondary (due to other disorders)
Primary dysmenorrhea
Primary dysmenorrhea is idiopathic and cannot be explained by other gynecologic disorders (1). Pain is thought to result from uterine contractions and ischemia, probably mediated by prostaglandins (eg, prostaglandin F2-alpha, a potent myometrial stimulant and vasoconstrictor) and other inflammatory mediators produced in secretory endometrium and possibly associated with prolonged uterine contractions and decreased blood flow to the myometrium.
Contributing factors may include the following:
Passage of menstrual tissue through the cervix
High levels of prostaglandin F2-alpha in menstrual fluid
A narrow cervical os
A malpositioned uterus
Anxiety
Primary dysmenorrhea typically begins within a year after menarche and occurs almost invariably in ovulatory cycles. The pain usually begins when menses start (or just before) and persists for the first 1 to 2 days; this pain, described as spasmodic, is superimposed over constant lower abdominal pain, which may radiate to the back or thigh. Patients may also have malaise, fatigue, nausea, vomiting, diarrhea, low back pain, or headache.
Risk factors for severe symptoms include the following:
Early age at menarche
Long or heavy menstrual periods
Smoking
A family history of dysmenorrhea
Symptoms tend to lessen with increasing age and after a first pregnancy.
Secondary dysmenorrhea
Symptoms of secondary dysmenorrhea are due to pelvic abnormalities. Almost any abnormality or process that can affect the pelvic viscera can cause dysmenorrhea.
Common causes of secondary dysmenorrhea include
Endometriosis (the most common cause)
Less common causes include congenital malformations (eg, bicornuate uterus, subseptate uterus, transverse vaginal septum), ovarian cysts and tumors, pelvic inflammatory disease, pelvic congestion, intrauterine adhesions, and intrauterine devices
In a few women, pain occurs when the uterus attempts to expel tissue through an extremely tight cervical os (secondary to conization, loop electrosurgical excision procedure [LEEP], or cryotherapy). Pain occasionally results from a pedunculated submucosal fibroid or an endometrial polyp protruding through the cervix.
Risk factors for severe secondary dysmenorrhea are the same as those for primary.
Secondary dysmenorrhea usually begins during adulthood unless caused by congenital malformations.
Etiology reference
1. Iacovides S, Avidon I, Baker FC: What we know about primary dysmenorrhea today: A critical review. Hum Reprod Update 21 (6):762–778, 2015. doi: 10.1093/humupd/dmv039. Epub 2015 Sep 7.
Evaluation of Dysmenorrhea
Clinicians can identify dysmenorrhea based on symptoms. They then determine whether dysmenorrhea is primary or secondary.
History
History of present illness should cover complete menstrual history, including age at onset of menses, duration and amount of flow, time between menses, variability of timing, and relation of menses to symptoms.
Clinicians should also ask about
The age at which symptoms began
Their nature and severity
Factors that relieve or worsen symptoms (including the effects of contraceptives)
Degree of disruption of daily life
Effect on sexual activity
Presence of pelvic pain unrelated to menses
Response to nonsteroidal anti-inflammatory drugs (NSAIDs)
History of dyspareunia or infertility (associated with endometriosis)
Review of systems should include accompanying symptoms such as cyclic nausea, vomiting, bloating, diarrhea, and fatigue.
Past medical history should identify known causes, including endometriosis, uterine adenomyosis, or fibroids. Method of contraception should be ascertained, specifically asking about IUD use.
Past surgical history should identify procedures that increase risk of dysmenorrhea, such as cervical conization and endometrial ablation.
Physical examination
Pelvic examination focuses on detecting causes of secondary dysmenorrhea. The cervix is examined for tenderness, discharge, cervical stenosis, or a prolapsed polyp or fibroid. Bimanual examination is performed to check for uterine masses and uterine consistency (a boggy uterus occurs in adenomyosis), adnexal masses, thickening of the rectovaginal septum, induration of the cul-de-sac, and nodularity of the uterosacral ligament.
The abdomen is examined for evidence of abnormal findings, including signs of peritonitis.
Red flags
The following findings are of particular concern in patients with dysmenorrhea:
New or sudden-onset pain
Unremitting pain
Fever
Purulent cervical discharge
Evidence of peritonitis
Interpretation of findings
Red flag findings suggest a cause of pelvic pain other than dysmenorrhea.
Primary dysmenorrhea is suspected if
Symptoms begin soon after menarche or during adolescence.
Secondary dysmenorrhea is suspected if
Symptoms begin after adolescence.
Patients have known causes, including uterine adenomyosis, fibroids, a tight cervical os, a mass protruding from the cervical os, or, particularly, endometriosis.
Endometriosis is considered in patients with adnexal masses, thickening of the rectovaginal septum, induration of the cul-de-sac, nodularity of the uterosacral ligament, or, occasionally, nonspecific vaginal, vulvar, or cervical lesions.
Testing
Testing aims to exclude structural gynecologic disorders. Most patients should have
Pregnancy testing
Pelvic ultrasonography
Pregnancy testing should be done in all women of reproductive age who present with pelvic pain. If pelvic inflammatory disease is suspected, cervical cultures are done.
Pelvic ultrasonography is highly sensitive for pelvic masses (eg, ovarian cysts, fibroids, endometriosis, uterine adenomyosis) and can locate abnormally located IUDs.
If these tests are inconclusive and symptoms persist, hysterosalpingography or sonohysterography may be done to identify endometrial polyps, submucous fibroids, or congenital abnormalities. MRI may be required to fully characterize congenital anomalies.
If results of all other tests are inconclusive, laparoscopy may be done, particularly if endometriosis is suspected.
Treatment of Dysmenorrhea
Nonsteroidal anti-inflammatory drugs (NSAIDs)
Often hormonal contraceptives
Treatment of underlying disorders
If identified, disorders causing dysmenorrhea are treated (eg, surgery to remove fibroids).
General measures
Measures to improve the patient's general well-being (eg, adequate rest and sleep, regular exercise) may be helpful. . Some patients find that a heating pad (used safely to avoid burns) applied to the lower abdomen alleviates pain.
Women with primary dysmenorrhea are reassured about the absence of other gynecologic disorders.
Medications
If pain is bothersome, NSAIDs (which relieve pain and inhibit prostaglandins) are typically tried. NSAIDs are usually started 24 to 48 hours before and continued until 1 or 2 days after menses begin.
If the NSAID is ineffective, suppression of ovulation with an estrogen/progestin contraceptive may be tried.
An NSAID or an NSAID plus an estrogen/progestin contraceptive is usually effective (1).
Other treatments
Endometriosis may be treated pharmacologically or with surgical fulguration of lesions.
For intractable pain of unknown origin, laparoscopic presacral neurectomy or uterosacral nerve ablation has been efficacious in some patients for as long as 12 months.
Hypnosis is being evaluated as treatment. Other proposed nonpharmacologic therapies, including acupuncture, acupressure, chiropractic therapy, transcutaneous electrical nerve stimulation
Treatment reference
1. Ferries-Rowe E, Corey E, Archer JS: Primary dysmenorrhea: Diagnosis and therapy. Obstet Gynecol 136 (5):1047–1058, 2020. doi: 10.1097/AOG.0000000000004096
Key Points
Most dysmenorrhea is primary.
Check for underlying gynecologic disorders.
Usually, do ultrasonography to check for structural gynecologic disorders.
An NSAID or an NSAID plus an estrogen/progestin contraceptive is usually effective.
