II. Epidemiology

  1. Onset occurs within 6 to 12 months of Menarche (may occur as long as 2 years from Menarche in some women)
  2. Prevalence peaks around age 20 years
  3. Lifetime Prevalence of severe Dysmenorrhea: 50-60%
  4. Women incapacitated for 1-3 days of each cycle: 10%

III. Pathophysiology

  1. No clear pelvic pathology
    1. Contrast with Secondary Dysmenorrhea in which an underlying organic etiology is identified
  2. Hormonal and inflammatory level increases with no clear pelvic pathology
    1. Increased Leukotriene levels
    2. Uterine hyperactivity with increased uterine contractility and cramping
      1. Increased myometrial resting tone >10 mmHg
      2. Increased contractile myometrial pressure >120 mmHg
      3. Increased frequency of uterine contractions
      4. Dysrhythmia of uterine contractions
    3. Increased Prostaglandin levels
      1. Increase in enzyme Prostaglandin Synthetase
      2. Increased Prostaglandins result in Vasoconstriction
      3. Prostaglandin mediated nerve terminal Hypersensitivity with high intensity contractions
    4. Vasopressin-mediated contractions
      1. Reduces uterine Blood Flow via Vasoconstriction
      2. May result in ischemic pain from uterine Hypoxia (uterine Angina)

IV. Symptoms

  1. See Dysmenorrhea
  2. Onset occurs within 6 to 12 months of Menarche and recurrs with each Menstrual Cycle

V. Examination

  1. See Dysmenorrhea
  2. Normal pelvic examination

VI. Differential Diagnosis

VIII. Precautions

  1. Primary Dysmenorrhea is a diagnosis of exclusion
  2. Exclude Secondary Dysmenorrhea causes (at minimum: pregnancy, Urinary Tract Infection and Sexually Transmitted Infection
    1. Older women without prior history of Dysmenorrhea should be assumed to have Secondary Dysmenorrhea until thorough evaluation is completed
    2. In young women, Secondary Dysmenorrhea still accounts for 10% of cases (especially due to Endometriosis)

IX. Management

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Ontology: Primary dysmenorrhea (C0149875)

Concepts Disease or Syndrome (T047)
ICD10 N94.4
SnomedCT 198405000, 237136000, 65754002
Dutch primaire dysmenorroe, dysmenorroe; primair, primair; dysmenorroe, Primaire dysmenorroe
French Dysménorrhée primitive
German primaere Dysmenorrhoe, Primaere Dysmenorrhoe
Italian Dismenorrea primaria
Portuguese Dismenorreia primária
Spanish Dismenorrea primaria, dismenorrea primaria, dismenorrea primaria (hallazgo), dismenorrea primaria (trastorno)
Japanese 原発性月経困難症, ゲンパツセイゲッケイコンナンショウ
Czech Primární dysmenorea
Korean 원발성 월경통
English primary dysmenorrhoea, primary dysmenorrhea, primary dysmenorrhea (diagnosis), dysmenorrhea primary, Primary dysmenorrhoea (disorder), Primary dysmenorrhoea (finding), Primary dysmenorrhea, Primary dysmenorrhoea, Primary dysmenorrhea (disorder), dysmenorrhea; primary, primary; dysmenorrhea, Primary dysmenorrhea (finding), Primary dysmenorrhoea [Ambiguous]
Hungarian Primaer dysmenorrhea, primaer dysmenorrhoea