Snapshot An 18-year-old nulligravid college woman complains of recurrent and cramping lower abdominal pain during menses for the past 3 years. She has nausea and vomiting during menses but denies irregular or heavy periods, pain with intercourse, or abdominal pain outside of menses. Pelvic exam is normal. She is recommended to take ibuprofen at the start of menses. Summary Overview dysmenorrhea is painful menses primary dysmenorrhea crampy, lower abdominal pain occurring during menses without any clear disease that can explain the symptoms secondary dysmenorrhea pain can be explained by other conditions (e.g., uterine fibroids, endometriosis, adenomyosis, and pelvic inflammatory disease) Epidemiology prevalence 50-90% of reproductive-age women worldwide most common gynecologic condition in women demographics onset typically a few months to years after menarche most commonly in those 16-24 years of age and prevalence declines progressively after 30 risk factors age < 30 body mass index (BMI) < 20 kg/m2 smoking long, heavy, or irregular periods decreased age at menarche sexual abuse Etiology Pathogenesis excess prostaglandins produced by the endometrium at the beginning of menses, causing high frequency uterine contractions, and increased intrauterine pressures when uterine pressure is greater than arterial pressure, there is uterine ischemia and the accumulated metabolites stimulate type C neural pain fibers resulting in dysmenorrhea Presentation History episodes usually first appear during adolescence, 6-12 months after menarche crampy, intermittent midline lower abdominal pain, which may radiate to lower back or thighs pain begins 1-2 days before menses and lasts up to 72 hours Symptoms crampy lower abdominal pain nausea vomiting headache fatigue diarrhea bloating Physical exam normal Differential Secondary dysmenorrhea (adenomyosis, endometriosis, and leiomyoma) key distinguishing factors will usually present > 25 years of age with abnormal uterine bleeding, dyspareunia, dyschezia, infertility, and an abnormal pevlic exam will have no response to treatment for primary dysmennorhea Pelvic inflammatory disease key distinguishing factors may present with fever will have abnormal pevlic exam findings such as cervical discharge, cervical motion tenderness, and adnexal or uterine tenderness Midcycle pain (mittelschmerz) key distinguishing factors will have unilateral abdominal pain will occur in the middle of the menstrual cycle, 10-14 days after menses start due to ovulation enlargement and rupture of follicular cyst causes irritation to the peritoneum Ovarian torsion key distinguishing factors will present with adnexal mass pain will have no relation to menses Treatment Management approach patients with no response to therapy should be re-evaluated for secondary dysmenorrhea Lifestyle heat packs exercise Medical nonsteroidal anti-inflammatory drugs (NSAIDS) indications considered first-line treatment for primary dysmenorrhea mechanism inhibition of prostaglandin synthesis combined hormonal or progestin-only contraceptives indications first-line treatment for primary dysmenorrhea in sexually active patients who also want to prevent pregnancy second-line treatment for those who do not respond to or cannot tolerate NSAIDs mechanism suppress ovulation, leading to decreased endometrial prostaglandin synthesis Surgical diagnostic laparoscopy indications option for patients with inadequate relief after 3-6 months of NSAID and/or hormonal contraceptive therapy to identify hidden endometriosis or pelvic pathology Complications Persistent pain Prognosis Natural history of disease tends to improve with age and childbirth Majority of cases respond to treatment