Dysmenorrhea

Dysmenorrhea is lower abdominal and pelvic pain that occurs shortly before and/or during menstruation. Primary dysmenorrhea is dysmenorrhea in the absence of pelvic pathology and is caused by an increase in prostaglandin levels. It typically begins 6–12 months after menarche and is common in adolescents and young adults. Symptoms may include low back pain, nausea, fatigue, diarrhea, and headaches. Primary dysmenorrhea is clinically diagnosed after excluding features that suggest secondary dysmenorrhea and mimics of dysmenorrhea. Treatment for primary dysmenorrhea includes NSAIDs for pain relief, hormonal contraceptives, and lifestyle modifications. Secondary dysmenorrhea results from an underlying condition such as endometriosis (most commonly), pelvic inflammatory disease (PID), or uterine fibroids. The diagnostic workup and management of secondary dysmenorrhea are based on the suspected condition.

Primary dysmenorrhea is lower abdominal and pelvic pain that occurs shortly before and/or during menstruation and is not caused by pelvic pathology.

Etiology ^[1][2]

Increased production of endometrial prostaglandins (PGF2α) causes:

• Hyperactive uterine contractions
• Uterine vasoconstriction → ischemia

Clinical features ^[1][3]

• Cyclic, crampy lower abdominal and/or pelvic pain ^[2]
  • Onset 6–12 months after menarche
  • Lasts 8–72 hours after onset of menstrual bleeding
  • Severity of pain is stable with each menstrual cycle.
• Additional symptoms may include:
  • GI symptoms (e.g., nausea, vomiting, diarrhea)
  • Headache
  • Fatigue, sleep disturbance
  • Muscle cramps
• Associated conditions
  • Premenstrual disorders
  • Depression
  • Anxiety

Pain associated with primary dysmenorrhea is typically midline and may radiate to the back or thighs. Consider secondary dysmenorrhea in patients with unilateral pain. ^[2]

Diagnosis ^[1][2][3]

• Primary dysmenorrhea is ; a clinical diagnosis and a diagnosis of exclusion.
• Make a presumptive diagnosis in patients with:
  • No features that suggest secondary dysmenorrhea ; or mimics of dysmenorrhea on detailed patient history
  • Negative pregnancy test (for patients who can become pregnant)

Pelvic examination and imaging are not required in adolescents with classic symptoms of primary dysmenorrhea. ^[1]

Treatment ^[1]

There is insufficient evidence to support a specific treatment algorithm for primary dysmenorrhea. Use initial therapies as monotherapy or combined therapy based on shared decision-making.

• Initial therapy
  • Pain relief with NSAIDs: Start any of the following 1–2 days before the menstrual cycle begins, and continue for 2–3 days into the cycle. : ^[1][4]
    • Ibuprofen (off-label)
    • Naproxen (off-label) ^[1]
    • See “Oral analgesics” for additional options.
  • Hormonal therapy: CHCs or progestin-only contraception ^[1][5]
  • Nonpharmacological measures: heating pads, exercise ^[6][7]
• Refractory dysmenorrhea ^[3]
  • Assess treatment adherence.
  • Consider diagnostic evaluation for secondary dysmenorrhea. ^[3]
  • Refer to a specialist (e.g., obstetrics and gynecology) for management.

Opioids are not recommended for the management of primary dysmenorrhea. ^[1][3]

Secondary dysmenorrhea is lower abdominal and pelvic pain that occurs shortly before and/or during menstruation and is caused by an underlying pelvic condition.

• Endometriosis (most common underlying cause)
• PID
• Adenomyosis
• Uterine fibroids
• Ovarian cysts or masses
• Endometrial polyps
• Stenosis of the cervical os
• Obstructive anomalies of the female genital tract (e.g., imperforate hymen, transverse vaginal septum)
• Intrauterine adhesions (i.e., Asherman syndrome) or pelvic adhesions
• Copper intrauterine device ^[8][9]

Endometriosis is the most common underlying cause of secondary dysmenorrhea. ^[3]

Focused history ^[1][3]

Obtain a complete medical, family, and gynecologic and obstetric history, including:

• Sexual history (e.g., risk factors for STIs)
• Clinical features that suggest secondary dysmenorrhea, e.g.:
  • Pain characteristics
    • Onset with menarche or > 25 years of age ^[3]
    • Sudden, severe, and/or progressively worsens
    • Noncyclical or mid-cycle
  • Associated symptoms
    • Abnormal vaginal discharge
    • Abnormal uterine bleeding (AUB)
    • Infertility
    • Dyspareunia
    • Clinical features of PID
  • Personal and family medical history
    • Family history of endometriosis
    • Congenital abnormalities (e.g., genitourinary, vertebral, cardiac, gastrointestinal)
    • History of procedural interventions (e.g., IUD placement, pelvic surgery) ^[3]
  • Unsuccessful empiric treatment for primary dysmenorrhea

Focused examination ^[1]

• Abdominal examination
• Pelvic examination: to assess for abnormalities suggesting an underlying cause of secondary dysmenorrhea, e.g.,
  • Uterine enlargement or irregularity
  • Cervical motion tenderness
  • Adnexal tenderness or mass
  • Vaginal or cervical discharge
  • Obstructive anomalies of the female genital tract

• Initial testing ^[1][3]
  • Pregnancy test for patients who can become pregnant
  • STI screening (e.g., NAAT for chlamydia and gonorrhea) in sexually active patients
  • Pelvic ultrasound
• Additional testing: may include the following based on suspected etiology ^[1][3]
  • Diagnostics to exclude mimics of dysmenorrhea (e.g., urinalysis for patients with urinary symptoms) ^[3]
  • Targeted testing for specific causes of secondary dysmenorrhea (e.g., diagnostics for endometriosis)

• Treat the underlying cause.
• If no cause is identified on diagnostic evaluation: ^[3]
  • Refer to obstetrics and gynecology.
  • Additional evaluation may include advanced imaging and/or surgery (e.g., laparoscopy to evaluate for endometriosis).

• Other causes of pelvic pain (e.g., endometritis, ectopic pregnancy)
• See also other causes of “Acute abdomen.”