Causes of dysmenorrhea ?
causes and etiology of dysmenorrhea primary secondary
pathophysiology prostaglandins dysmenorrhea endometriosis
| Mechanism | Details |
|---|---|
| Prostaglandin (PG) overproduction | Elevated PGF2α and PGE2 in the endometrium trigger intense myometrial contractions and uterine ischemia, producing pain |
| Uterine hypercontractility | PG-driven contractions exceed normal intrauterine pressure, reducing blood flow (uterine angina) |
| Peripheral nerve hypersensitivity | Prostaglandins sensitize nociceptors, amplifying pain signals |
| PG-independent pathways | Platelet-activating factor (PAF) and other inflammatory mediators may contribute in women who do not respond to COX inhibitors |
| Vasopressin | Causes non-rhythmic uterine contractions and vasospasm, contributing to ischemia |
Key features: Onset with ovulatory cycles, begins with menstrual flow, lasts 12–72 hours, associated with nausea, diarrhea, fatigue, and headache. Prevalence 60–93% in adolescents; decreases after pregnancy and with oral contraceptive use. (Harrison's, p. 11064)
| Cause | Notes |
|---|---|
| Endometriosis | Ectopic endometrial tissue responds to hormonal cycles; associated with dyspareunia, dyschezia, and tender uterosacral nodules. Stage does not always correlate with pain severity (Harrison's, p. 11064) |
| Adenomyosis | Endometrial glands within the myometrium; causes heavy, painful periods; uterus is bulky and tender |
| Uterine fibroids (leiomyomata) | Particularly submucosal fibroids; distort the endometrial cavity and increase PG release |
| Endometrial polyps | Intrauterine lesions causing abnormal uterine contractions |
| Pelvic Inflammatory Disease (PID) | Infection/inflammation of upper genital tract; may cause chronic pelvic pain and dysmenorrhea |
| Cervical stenosis | Obstructs menstrual outflow, raising intrauterine pressure |
| Intrauterine device (IUD) | Copper IUDs can worsen dysmenorrhea; foreign body increases local PG production |
| Pelvic adhesions | Post-surgical or post-infectious scarring restricts pelvic organ movement |
| Ovarian cysts | Especially endometriomas (chocolate cysts); may rupture or cause torsion |
| Congenital anomalies | Obstructive Müllerian anomalies (e.g., imperforate hymen, transverse vaginal septum, bicornuate uterus) cause outflow obstruction |
| Feature | Primary | Secondary |
|---|---|---|
| Onset | Shortly after menarche, with ovulatory cycles | Later in life or change in pattern |
| Pelvic exam | Normal | Abnormal findings may be present |
| Response to NSAIDs | Usually good | Often incomplete |
| Duration | 12–72 h from onset of flow | May persist throughout or outside menses |
Investigations and treatment
dysmenorrhea investigations workup diagnosis pelvic ultrasound laparoscopy
dysmenorrhea treatment NSAIDs oral contraceptives management
| Test | Purpose |
|---|---|
| Pregnancy test (urine/serum β-hCG) | Rule out ectopic pregnancy |
| High vaginal / endocervical swabs | Rule out PID, STIs (Chlamydia, Gonorrhea) |
| CBC | Assess for anaemia (heavy periods) |
| CA-125 | May be elevated in endometriosis; low negative predictive value — not diagnostic alone (Harrison's, p. 11064) |
| ESR / CRP | If infection or inflammatory cause suspected |
| Investigation | Indication & Findings |
|---|---|
| Transvaginal pelvic ultrasound (TVUS) | First-line imaging; detects endometriomas, fibroids, polyps, ovarian cysts, adenomyosis (heterogeneous myometrium, myometrial cysts) (Harrison's, p. 11064) |
| Transabdominal ultrasound | Used when TVUS is not appropriate (e.g., virginal patients) |
| MRI pelvis | Superior for adenomyosis and deep infiltrating endometriosis; used when TVUS is inconclusive |
| Hysteroscopy | Direct visualisation of uterine cavity; detects polyps, fibroids, septa, synechiae |
| Diagnostic laparoscopy | Gold standard for endometriosis diagnosis; performed when empirical treatment fails; allows simultaneous surgical treatment (Harrison's, p. 11064) |
| Hysterosalpingography (HSG) | Evaluates uterine cavity and tubal patency; useful if Müllerian anomalies suspected |
| Agent | Notes |
|---|---|
| Combined oral contraceptives (COCPs) | Taken cyclically or continuously; suppresses ovulation and endometrial proliferation, reducing PG levels (Harrison's, p. 11065) |
| Progestin-only pills / Depo-Provera | Useful if oestrogen is contraindicated |
| Levonorgestrel IUS (Mirena) | Reduces menstrual flow and dysmenorrhea significantly |
| GnRH analogues | Reserved for refractory cases; cause a hypoestrogenic state |
| Intervention | Evidence |
|---|---|
| Local heat application | Effective; proven benefit (Harrison's, p. 11065) |
| Exercise | Suggested benefit; increases endorphins |
| Dietary modifications | Vegetarian diet, fish oil (omega-3), reduced caffeine |
| Supplements | Vitamins D, B₁, B₆, E — suggested benefit but studies insufficient for firm recommendations (Harrison's, p. 11065) |
| Acupuncture / Yoga | Some evidence; not yet guideline-recommended |
| Sexual activity | Suggested anecdotal benefit |
| Cause | Treatment |
|---|---|
| Endometriosis | NSAIDs + COCPs (empiric first); if refractory → diagnostic laparoscopy with ablation/excision of lesions; GnRH agonists for medical suppression |
| Adenomyosis | COCPs, LNG-IUS, GnRH agonists; definitive treatment is hysterectomy |
| Uterine fibroids | Uterine artery embolisation, myomectomy, or hysterectomy depending on size/location/fertility goals |
| PID | Appropriate antibiotics (e.g., doxycycline + metronidazole ± ceftriaxone) |
| Cervical stenosis | Cervical dilatation |
| Copper IUD-related | Switch to LNG-IUS; add NSAIDs |
| Congenital anomalies | Surgical correction |
Dysmenorrhea
│
├─ Normal exam, young patient → Primary dysmenorrhea
│ └─ NSAIDs (start before menses) ──→ Response? ──Yes──→ Continue
│ │
│ No
│ ↓
│ Add COCPs / LNG-IUS
│ │
│ Still failing?
│ ↓
│ Investigate as secondary
│
└─ Abnormal exam / older onset / refractory → Secondary dysmenorrhea
└─ TVUS → MRI if needed → Laparoscopy if no response to empiric Rx
└─ Treat specific underlying pathology