Dysmenorrhea

A comprehensive chapter on Dysmenorrhea that covers all the essential aspects medical students and doctors need to understand. The chapter is structured to provide both foundational knowledge and practical clinical guidance.

Dysmenorrhea

Overview

Dysmenorrhea is defined as painful menstruation that interferes with daily activities and represents one of the most common gynecological complaints, affecting up to 90% of adolescents and young women. It is the leading cause of recurrent short-term school and work absence in young women, creating significant healthcare costs and productivity losses.

Classification

Primary Dysmenorrhea

  • Painful menstruation without identifiable pelvic pathology

  • Typically begins 6-12 months after menarche when ovulatory cycles are established

  • Usually starts with or just before menstrual flow

  • Pain duration: 1-3 days

  • Most common in adolescents and women under 25

Secondary Dysmenorrhea

  • Painful menstruation associated with underlying pelvic pathology

  • May occur at any age but more common after age 25

  • Pain may begin before menstruation and persist throughout the cycle

  • Often progressive in nature

  • Increases with age, particularly after 30

Pathophysiology

Primary Dysmenorrhea The pathophysiology involves several interconnected mechanisms:

  • Prostaglandin Pathway: Endometrial prostaglandin F2α (PGF2α) and prostaglandin E2 (PGE2) production increases dramatically during menstruation. PGF2α causes intense myometrial contractions and vasoconstriction. Elevated prostaglandin levels correlate with pain severity.

  • Vascular Changes: Vasoconstriction reduces endometrial blood flow, causing tissue hypoxia and ischemia that contribute to pain.

  • Neurological Factors: Sensitization of pain pathways and central pain processing alterations occur.

Secondary Dysmenorrhea Pain results from underlying pathological conditions affecting pelvic structures through:

  • Mechanical obstruction to menstrual flow

  • Inflammatory processes

  • Structural abnormalities

  • Hormonal imbalances

Epidemiology

  • Prevalence: 45-95% of reproductive-age women

  • Age distribution: Primary dysmenorrhea most common in adolescents; secondary increases with age

  • Economic impact: Significant healthcare costs and productivity losses globally

Presentation

History

Pain Characteristics

  • Location: Lower abdomen, may radiate to back and thighs

  • Quality: Cramping, colicky, or constant aching

  • Timing: Relationship to menstrual cycle

    • Primary: Pain starts with or just before menstrual flow

    • Secondary: Pain may begin before menstruation and persist throughout cycle

  • Duration: Hours to days

  • Severity: Use validated pain scales (Visual Analog Scale, Numeric Rating Scale)

  • Progression: Primary usually stable; secondary often worsening over time

Associated Symptoms

  • Nausea and vomiting (common in primary)

  • Diarrhea or constipation

  • Headache

  • Fatigue

  • Mood changes

  • Breast tenderness

  • Dizziness or syncope (severe cases)

Menstrual History

  • Age of menarche

  • Cycle length and regularity

  • Flow characteristics (duration, volume, clots)

  • Previous menstrual patterns

  • Age of onset of dysmenorrhea

Gynecological History

  • Sexual activity and contraceptive use

  • Previous pelvic infections or STIs

  • Previous gynecological procedures or surgeries

  • Pregnancy history

  • Dyspareunia (painful intercourse)

Additional History

  • Family history of gynecological conditions (endometriosis, fibroids)

  • Impact on quality of life and daily activities

  • School or work absence patterns

  • Previous treatments tried and their effectiveness

  • Medications and allergies

Red Flags Suggesting Secondary Dysmenorrhea

  • New onset of severe pain after age 25

  • Pain not responsive to NSAIDs and hormonal therapy

  • Progressive worsening of symptoms

  • Irregular menstrual patterns

  • Intermenstrual bleeding

  • Postcoital bleeding

  • Pelvic pain outside of menstruation

  • Systemic symptoms (fever, weight loss)

Physical Examination

General Examination

  • Vital signs during acute episodes

  • Assessment of pain behavior and distress level

  • Signs of anemia (pallor, fatigue) if heavy bleeding present

  • Body mass index and general nutritional status

Abdominal Examination

  • Inspection for distension, scars, or visible masses

  • Auscultation for bowel sounds

  • Palpation for:

    • Tenderness or masses

    • Organomegaly

    • Bladder distension

  • Assessment for rebound tenderness or guarding

  • Costovertebral angle tenderness

Pelvic Examination (when appropriate and patient consents)

Note: Pelvic examination may be deferred in adolescents with typical primary dysmenorrhea who are not sexually active

External Genitalia

  • Inspection for lesions, discharge, or anatomical abnormalities

  • Assessment of Tanner staging in adolescents

Speculum Examination

  • Visualize cervix for lesions, discharge, or bleeding

  • Assess cervical os (stenosis may suggest obstruction)

  • Collect specimens if indicated (Pap smear, STI testing)

Bimanual Examination

  • Uterine assessment:

    • Size, shape, and consistency

    • Mobility and position

    • Tenderness

  • Adnexal examination:

    • Masses or enlargement

    • Tenderness

    • Mobility

  • Cervical motion tenderness

  • Parametrial assessment

Rectovaginal Examination (if indicated)

  • Assess for posterior uterine masses

  • Evaluate uterosacral ligament nodularity (endometriosis)

  • Assess rectal lesions or masses

Differential Diagnosis

Primary Dysmenorrhea

  • Essential dysmenorrhea with no identifiable pelvic pathology

  • Diagnosis of exclusion in typical presentations

Secondary Dysmenorrhea - Gynecological Causes

Common Causes

  • Endometriosis: Most common cause of secondary dysmenorrhea

    • Deep dyspareunia, chronic pelvic pain

    • May have cyclical symptoms

  • Adenomyosis: Enlarged, tender uterus

    • Heavy menstrual bleeding

    • More common in multiparous women >35

  • Uterine fibroids (leiomyomas): Enlarged, irregular uterus

    • Heavy or prolonged bleeding

    • Bulk symptoms

  • Pelvic inflammatory disease (PID): Cervical motion tenderness

    • Purulent discharge, fever

    • Risk factors: multiple partners, STIs

  • Ovarian cysts: Adnexal masses on examination

    • May cause intermittent pain

  • Cervical stenosis: Decreased menstrual flow

    • History of cervical procedures

Less Common Gynecological Causes

  • Congenital uterine anomalies (bicornuate uterus, uterine septum)

  • Intrauterine adhesions (Asherman syndrome)

  • Endometrial polyps

  • Copper intrauterine device complications

  • Pelvic congestion syndrome

  • Ovarian endometriomas

  • Müllerian duct anomalies

Non-Gynecological Causes

Gastrointestinal

  • Irritable bowel syndrome

  • Inflammatory bowel disease

  • Appendicitis (acute cases)

  • Constipation

Urological

  • Urinary tract infection

  • Kidney stones

  • Interstitial cystitis

Musculoskeletal

  • Myofascial pelvic pain

  • Coccydynia

Other

  • Psychological factors (anxiety, depression)

  • Somatization disorders

Workup

Primary Dysmenorrhea

  • Clinical diagnosis in typical presentations:

    • Young woman with cyclical pelvic pain

    • Pain begins with menstruation

    • Duration 1-3 days

    • No abnormal physical findings

  • Therapeutic trial with NSAIDs supports diagnosis

  • Further workup indicated if:

    • Atypical presentation

    • Poor response to treatment

    • Red flags present

Secondary Dysmenorrhea Workup

Laboratory Tests

  • Complete blood count (CBC): Assess for anemia from heavy bleeding

  • Pregnancy test (β-hCG): Rule out pregnancy complications

  • Urinalysis: Exclude urinary tract infection

  • STI screening:

    • Nucleic acid amplification tests for chlamydia and gonorrhea

    • Consider other STIs based on risk factors

  • Inflammatory markers: ESR, CRP if PID suspected

  • Additional tests as indicated:

    • Thyroid function tests

    • Coagulation studies if bleeding disorder suspected

Imaging Studies

Transvaginal Ultrasound (first-line imaging)

  • Evaluate uterine size, shape, and echo texture

  • Assess endometrial thickness and morphology

  • Identify ovarian pathology (cysts, masses)

  • Assess for free fluid in pelvis

  • Doppler studies if indicated

Magnetic Resonance Imaging (MRI)

  • Superior soft tissue contrast

  • Indications:

    • Suspected adenomyosis

    • Deep infiltrating endometriosis

    • Complex adnexal masses

    • Congenital uterine anomalies

    • When ultrasound inconclusive

Other Imaging

  • Hysterosalpingography (HSG): Assess uterine cavity and tubal patency

  • Hysterosonography (SIS): Evaluate intrauterine pathology

  • CT scan: Rarely indicated, mainly for acute complications

Invasive Procedures

Laparoscopy

  • Gold standard for endometriosis diagnosis

  • Indications:

    • Severe dysmenorrhea unresponsive to medical therapy

    • Suspected endometriosis with negative imaging

    • Adnexal masses requiring surgical evaluation

    • Chronic pelvic pain evaluation

Hysteroscopy

  • Direct visualization of uterine cavity

  • Indications:

    • Abnormal uterine bleeding

    • Suspected intrauterine pathology

    • Failed medical management

Endometrial Biopsy

  • Indications:

    • Abnormal uterine bleeding in women >35

    • Suspected endometrial pathology

    • Risk factors for endometrial hyperplasia/cancer

Diagnostic Algorithm

  1. Initial Assessment: History and physical examination

  2. Primary Dysmenorrhea Suspected: Therapeutic trial with NSAIDs

  3. Good Response: Continue treatment, follow up as needed

  4. Poor Response or Red Flags: Proceed with workup for secondary causes

  5. Laboratory Tests: As indicated by clinical presentation

  6. Imaging: Start with transvaginal ultrasound

  7. Advanced Imaging/Procedures: Based on initial findings

Treatment

General Principles

  • Patient education and reassurance about the condition

  • Individualized approach based on patient factors and preferences

  • Address both pain management and underlying pathology

  • Consider impact on quality of life and daily activities

  • Multidisciplinary approach may be beneficial

Primary Dysmenorrhea Treatment

First-Line Therapy

  • NSAIDs: Most effective when started before pain onset

  • Patient education: Timing of medication crucial for effectiveness

  • Lifestyle modifications: Heat therapy, exercise, stress management

Second-Line Therapy

  • Hormonal contraceptives: Particularly for women seeking contraception

  • Continuous/extended cycling: May be more effective than cyclic regimens

Alternative and Complementary Approaches

  • Topical heat: Heat pads or warm baths

  • Exercise: Regular aerobic exercise and stretching

  • Dietary supplements:

    • Omega-3 fatty acids

    • Vitamin B1 (thiamine)

    • Magnesium

    • Vitamin D

  • Mind-body techniques: Yoga, meditation, relaxation techniques

  • Acupuncture: Some evidence for pain reduction

  • Transcutaneous electrical nerve stimulation (TENS)

Secondary Dysmenorrhea Treatment

Treatment focuses on addressing the underlying pathology:

Endometriosis

  • Medical management:

    • Combined oral contraceptives

    • Progestins (dienogest, norethindrone)

    • GnRH agonists with add-back therapy

    • GnRH antagonists

  • Surgical management:

    • Laparoscopic excision or ablation

    • Conservative vs definitive surgery

Adenomyosis

  • Medical management:

    • Progestins (LNG-IUD most effective)

    • GnRH agonists

    • Tranexamic acid for heavy bleeding

  • Surgical options:

    • Hysterectomy for completed fertility

    • Uterine artery embolization

Uterine Fibroids

  • Medical management:

    • GnRH agonists for symptom relief

    • Selective progesterone receptor modulators

    • Tranexamic acid for bleeding

  • Minimally invasive procedures:

    • Uterine artery embolization

    • MRI-guided focused ultrasound

  • Surgical options:

    • Myomectomy (preserve fertility)

    • Hysterectomy (definitive treatment)

Pelvic Inflammatory Disease

  • Antibiotic therapy according to CDC guidelines

  • Partner treatment essential

  • Follow-up to ensure cure

Other Conditions

  • Ovarian cysts: Observation vs surgical management

  • Cervical stenosis: Cervical dilation procedures

  • Congenital anomalies: Surgical correction as appropriate

Treatment Selection Factors

  • Age and reproductive plans

  • Severity of symptoms

  • Contraceptive needs

  • Comorbidities and contraindications

  • Patient preferences

  • Cost and insurance coverage

  • Previous treatment responses

Medications

Nonsteroidal Anti-inflammatory Drugs (NSAIDs)

Mechanism of Action

  • Inhibit cyclooxygenase enzymes (COX-1 and COX-2)

  • Reduce prostaglandin synthesis

  • Decrease uterine contractions and inflammation

Specific Medications

Ibuprofen

  • Dosage: 400-600 mg every 6 hours

  • Maximum daily dose: 2400 mg

  • Onset: 30-60 minutes

  • Duration: 6-8 hours

Naproxen

  • Dosage: 220-550 mg every 12 hours

  • Maximum daily dose: 1100 mg

  • Onset: 1-2 hours

  • Duration: 12 hours

  • Advantage: Twice daily dosing

Diclofenac

  • Dosage: 50 mg every 8 hours

  • Maximum daily dose: 150 mg

  • Available forms: Oral, topical gel

  • Topical: Useful for GI-sensitive patients

Mefenamic Acid

  • Dosage: 250-500 mg every 8 hours

  • Maximum treatment: 7 days per cycle

  • Specific indication: Particularly effective for dysmenorrhea

Celecoxib (COX-2 selective)

  • Dosage: 200 mg twice daily

  • Advantage: Lower GI side effect profile

  • Cost: More expensive than traditional NSAIDs

NSAID Prescribing Guidelines

  • Start 1-2 days before expected menstruation

  • Continue for 2-3 days or until pain resolves

  • Take with food to reduce GI irritation

  • Adequate hydration important

Contraindications to NSAIDs

  • Active peptic ulcer disease

  • History of GI bleeding

  • Severe renal impairment

  • Severe heart failure

  • Known hypersensitivity

  • Third trimester pregnancy

Side Effects and Monitoring

  • Common: GI upset, nausea, dizziness

  • Serious: GI bleeding, renal impairment, cardiovascular events

  • Monitoring: Renal function, blood pressure in long-term use

Hormonal Medications

Combined Oral Contraceptives

Mechanism: Suppress ovulation, reduce endometrial prostaglandin production

Formulations:

  • Monophasic: Consistent hormone levels (preferred for dysmenorrhea)

  • Low-dose estrogen: 20-35 mcg ethinyl estradiol

  • Extended cycle: Reduce frequency of menstruation

Specific Options:

  • Ethinyl estradiol 20-30 mcg + Levonorgestrel 0.15 mg

  • Ethinyl estradiol 30 mcg + Drospirenone 3 mg

  • Ethinyl estradiol 20 mcg + Norethindrone acetate 1 mg

Contraindications:

  • Thromboembolism history

  • Cerebrovascular disease

  • Coronary artery disease

  • Migraine with aura

  • Active liver disease

  • Estrogen-dependent malignancy

  • Unexplained vaginal bleeding

  • Smoking >35 years old

Other Hormonal Contraceptives

Progestin-Only Options:

  • Depot medroxyprogesterone acetate: 150 mg IM every 3 months

  • Levonorgestrel IUD: 52 mg, effective for 5 years

  • Etonogestrel implant: Single rod, effective for 3 years

Advantages: Can be used when estrogen contraindicated

Specialized Medications for Secondary Dysmenorrhea

GnRH Agonists

  • Leuprolide: 3.75 mg IM monthly or 11.25 mg every 3 months

  • Goserelin: 3.6 mg subcutaneous monthly

  • Nafarelin: Nasal spray, 200 mcg twice daily

  • Use: Endometriosis, adenomyosis, fibroids

  • Duration: Usually limited to 6 months without add-back therapy

  • Add-back therapy: Low-dose estrogen/progestin to prevent bone loss

GnRH Antagonists

  • Elagolix: 150-200 mg twice daily

  • Newer option: For endometriosis-associated pain

  • Advantage: Faster onset than agonists

Progestins for Endometriosis

  • Dienogest: 2 mg daily

  • Norethindrone acetate: 5-15 mg daily

  • Medroxyprogesterone acetate: 20-30 mg daily

Topical Medications

Topical NSAIDs

  • Diclofenac gel: Apply to lower abdomen

  • Advantage: Reduced systemic side effects

  • Use: Patients with GI contraindications to oral NSAIDs

Adjunctive Medications

Antispasmodics

  • Hyoscine butylbromide: 20 mg three times daily

  • Limited evidence: May help with cramping pain

Analgesics

  • Acetaminophen: 500-1000 mg every 6 hours

  • Role: Adjunct to NSAIDs, not first-line for dysmenorrhea

  • Combination products: Often combined with NSAIDs

Medication Selection Guidelines

First-Line for Primary Dysmenorrhea:

  1. NSAIDs (ibuprofen, naproxen, mefenamic acid)

  2. Combined oral contraceptives if contraception desired

Second-Line Options:

  1. Alternative NSAID if first choice ineffective

  2. Hormonal contraceptives (various forms)

  3. Combination of NSAID + hormonal method

For Secondary Dysmenorrhea:

  • Treatment specific to underlying condition

  • May require specialized medications (GnRH agonists, specific progestins)

Special Populations:

  • Adolescents: NSAIDs first-line, contraceptives if sexually active

  • Adults planning pregnancy: Avoid hormonal methods

  • Contraindications to hormones: Focus on NSAIDs and non-pharmacological approaches

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