Epidemiology & Risk Factors

Primary Dysmenorrhea:
- Onset typically 6–24 months post-menarche (establishment of regular ovulatory cycles).
- Peak prevalence in late adolescence/early adulthood (<25 yo).
- Risk factors: Age <30, menarche <12 yo, nulliparity, smoking, heavy/prolonged menses, family history.
Secondary Dysmenorrhea:
- Onset typically >25 yo, or worsening symptoms in previously mild cycles.
- Risk factors: Prior pelvic surgery/infections, multiparity (adenomyosis), positive family history (endometriosis).

Clinical Features

Primary Dysmenorrhea:
- Pathophysiology: Excess endometrial prostaglandin production (PGF2α, PGE2) causing uterine hypercontractility and myometrial ischemia.
- History: Recurrent, crampy, midline lower abdominal/suprapubic pain starting 1–2 days prior to or with the onset of menses; resolves within 12–72 hours.
- Associated Symptoms: Nausea, vomiting, diarrhea, headache, fatigue (due to systemic PG release).
- Physical Exam: Completely normal pelvic exam (normal uterine size, mobility, and absence of adnexal masses/tenderness). c
Secondary Dysmenorrhea:
- History: Pain often starts days before menses, lasts throughout cycle, or occurs mid-cycle; variable response to standard medical therapy.
- Physical Exam (findings depend on etiology):
  - Endometriosis: Uterosacral ligament nodularity, fixed/retroverted uterus, adnexal tenderness/mass (endometrioma), pain with cervical motion.
  - Adenomyosis: Symmetrically enlarged, globular, tender, “boggy” uterus.
  - Leiomyomas (Fibroids): Irregularly enlarged, firm, nodular, non-tender uterus.
  - Pelvic Inflammatory Disease (PID): Purulent cervical discharge, cervical motion tenderness (CMT), bilateral adnexal tenderness.

Initial / Screening:
- Urine Pregnancy Test (UPT): Mandatory initial step to rule out pregnancy-related complications (e.g., ectopic pregnancy, spontaneous abortion).
- Pelvic / Transvaginal Ultrasound (TVUS):
  - Indicated if: Secondary dysmenorrhea is suspected, abnormal pelvic exam findings, age ≥25 at onset, or failure of empiric therapy.
  - Visualizes leiomyomas, adenomyosis (heterogeneous myometrium), and endometriomas (“ground-glass” appearance).
- STI NAAT (Chlamydia trachomatis, Neisseria gonorrhoeae): If PID or cervicitis is suspected.
Primary Dysmenorrhea:
- Clinical diagnosis: Adolescent/young female, typical onset/timing, absence of systemic “red flags”, and normal physical/pelvic exam. No imaging required initially.
Confirmatory / Gold Standard:
- Endometriosis: Diagnostic laparoscopy with biopsy (visualization of “powder-burn” or “chocolate” lesions).
- Adenomyosis: Pelvic MRI (thickened junctional zone >12 mm) or Histopathological examination post-hysterectomy (definitive).

Endometriosis:
- Differentiating features: “3 Ds” (Dysmenorrhea, Dyspareunia, Dyschezia), chronic pelvic pain, infertility, pain non-responsive to NSAIDs, fixed retroverted uterus.
Adenomyosis:
- Differentiating features: Typically multiparous women >40 yo, coexists with heavy menstrual bleeding (HMB), uniformly enlarged, globular, tender uterus.
Uterine Leiomyoma (Submucosal/Intramural):
- Differentiating features: Heavy/prolonged menstrual bleeding, pelvic pressure/bulk symptoms, irregularly enlarged/contoured uterus on bimanual exam.
Pelvic Inflammatory Disease (PID):
- Differentiating features: Intermenstrual bleeding, abnormal vaginal/cervical discharge, fever, leukocytosis, acute CMT and adnexal tenderness.
Cervical Stenosis:
- Differentiating features: History of cervical instrumentation (e.g., LEEP, conization, cryotherapy), scant menstrual flow/amenorrhea with severe cyclic pain (hematometra).

Primary Dysmenorrhea:
- First-line:
  - NSAIDs (e.g., Ibuprofen, Naproxen, Mefenamic acid): Inhibit cyclooxygenase (COX), reducing PG synthesis. Best initiated 1–2 days prior to menses onset.
  - Combined Hormonal Contraceptives (CHCs) (pills, patch, vaginal ring) or Levonorgestrel Intrauterine Device (LNG-IUD): Suppresses ovulation and thins the endometrium, reducing PG production.
- Second-line / Alternate:
  - Switch to alternative NSAID class or alternative hormonal method (e.g., DMPA, Progestin-only pills, Etonogestrel implant).
- Refractory (Unresponsive to 3–6 months of NSAIDs + CHCs):
  - Proceed to Pelvic Ultrasound and/or Diagnostic Laparoscopy to evaluate for secondary etiologies (primarily endometriosis).
Secondary Dysmenorrhea:
- Directed at underlying cause:
  - Endometriosis: First-line CHCs/Progestins $\to$ GnRH agonists/antagonists (e.g., Leuprolide, Elagolix) with add-back therapy $\to$ Laparoscopic surgical ablation/excision.
  - Adenomyosis: LNG-IUD, continuous CHCs, tranexamic acid $\to$ Hysterectomy (definitive treatment for women who have completed childbearing).
  - Leiomyomas: Myomectomy (fertility-sparing), Uterine Artery Embolization (UAE), or Hysterectomy.

Primary:
- Significant school and workplace absenteeism.
- Decreased quality of life and sleep disturbance.
- Central sensitization predisposing to chronic pelvic pain syndromes.
Secondary:
- Infertility / Subfertility (endometriosis, chronic PID).
- Severe Iron Deficiency Anemia (secondary to HMB from adenomyosis/fibroids).
- Pelvic adhesions, bowel/bladder obstruction (severe deep infiltrating endometriosis).

tags	—
aliases