Dysmenorrhea: Definition & Types - Period Pain Primer
- Definition: Painful menstruation, typically cramping in the lower abdomen, occurring just before or during menses.
- Types:
- Primary: No underlying pelvic pathology. Common in adolescents.
⭐ Primary dysmenorrhea typically begins 6-12 months after menarche, coinciding with the onset of ovulatory cycles.
- Secondary: Due to underlying pelvic pathology (e.g., endometriosis, fibroids, adenomyosis, PID). More common in women aged >25 years.
- Primary: No underlying pelvic pathology. Common in adolescents.
- Prevalence: Affects up to 90% of adolescent girls and 25-50% of reproductive-age women globally; a leading cause of recurrent short-term school/work absenteeism.
Primary Dysmenorrhea: Pathophys & Features - Prostaglandin Party Poopers
- Pathophysiology:
- ↑ Prostaglandins (esp. $PGF_{2\alpha}$, $PGE_2$) & leukotrienes released from shedding endometrium during menses.
- Causes intense uterine hypercontractility, ↓ uterine blood flow & myometrial ischemia → colicky pain.
- Clinical Features:
- Crampy, spasmodic, midline lower abdominal/suprapubic pain.
- Often radiates to the lower back or inner thighs.
- Onset: Usually a few hours prior to or with menses; lasts 1-3 days, typically peaks at 24-48 hrs.
- Associated symptoms: Nausea, vomiting, diarrhea, headache, fatigue, dizziness.

⭐ Increased levels of $PGF_{2\alpha}$ in menstrual fluid are directly correlated with the severity of primary dysmenorrhea.
Secondary Dysmenorrhea: Causes & Clues - Underlying Culprits Unmasked
| Cause | Onset Age | Pain Features | Key Associations |
|---|---|---|---|
| Endometriosis | Repro | Progressive, cyclical; deep dyspareunia | Infertility, cyclical sx (bowel/bladder), endometrioma |
| Adenomyosis | >30 yrs | Menorrhagia; boggy, tender, ↑uterus | Dyspareunia; AUB (📌 PALM-COEIN) |
| Fibroids | Repro | AUB, pressure; pain if degen | Asymm. ↑uterus (firm); AUB (📌 PALM-COEIN) |
| PID | Repro | Acute/chronic bilateral pelvic pain | Fever, discharge, CMT, adnexal tender |
| Cervical Stenosis | Post-proc | Cramping post scant/absent flow | Hx cervical surgery |
| Ovarian Cysts | Any | Unilateral; acute if torsion/rupture | Adnexal mass |
| Congenital Anom. | Adolescence | Cyclical, severe; outflow obstruction | Hematocolpos/hematometra |

Dysmenorrhea: Diagnosis & Workup - Detective Work
- History: Detailed pain characteristics (onset, duration, severity, cycle relation, impact), associated symptoms, menstrual history, sexual history.
- Red Flags: New onset after age 25, Abnormal Uterine Bleeding (AUB), infertility, deep dyspareunia, failure to respond to NSAIDs/OCPs.
- Examination: General, abdominal, and pelvic (bimanual for uterine/adnexal assessment, speculum for cervical/vaginal view).
- Investigations:
- Transvaginal Ultrasound (TVS): Initial imaging of choice.
- MRI or Hysteroscopy: For complex cases or if TVS is non-diagnostic.
- Laparoscopy: Gold standard for endometriosis or pelvic adhesions.
⭐ New onset dysmenorrhea after the age of 25 years strongly suggests a secondary cause.
Dysmenorrhea: Management Strategies - Pain Relief Playbook
- Primary Dysmenorrhea:
- NSAIDs: Mefenamic acid (500mg TDS), Ibuprofen (400-600mg TDS). Start 1-2 days before menses.
- COCs, Progestogens (DMPA, LNG-IUS).
- Non-pharmacological: Heat, exercise, TENS.
- Secondary Dysmenorrhea: Treat underlying cause.
- Endometriosis: GnRH agonists, surgery.
- Fibroids: Myomectomy.
- PID: Antibiotics.
- Hysterectomy (last resort).
⭐ NSAIDs are first-line for primary dysmenorrhea, most effective when started 1-2 days before menses and continued for 2-3 days of bleeding.
High‑Yield Points - ⚡ Biggest Takeaways
- Primary dysmenorrhea: Excess prostaglandins; onset 6-12 months post-menarche with ovulatory cycles.
- Secondary dysmenorrhea: Due to pelvic pathology (endometriosis, adenomyosis, fibroids, PID).
- NSAIDs are first-line treatment for primary dysmenorrhea, inhibiting prostaglandins.
- Combined oral contraceptives (COCs) reduce pain by inhibiting ovulation and endometrial growth.
- Endometriosis: Common cause of progressive dysmenorrhea, dyspareunia, infertility.
- Adenomyosis: Presents with dysmenorrhea & menorrhagia; uterus symmetrically enlarged.
- Laparoscopy: Gold standard to diagnose endometriosis or pelvic adhesions causing secondary dysmenorrhea.
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