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Menstrual Bleeding

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Menstrual Bleeding, Menses, Menarche, Menstruation

  • See Also
  1. Menstrual Cycle
  2. Amenorrhea
  3. Abnormal Uterine Bleeding
  • Definitions
  1. Normal Cycles
    1. Cycle Duration: 28 days (21-35 days)
    2. Days of Flow: 4.6 days (2-8 days)
    3. Estimated Blood Loss: 35 ml per cycle (20-80 ml)
  2. Abnormal Cycle Length
    1. Polymenorrhea: Cycle less than 21 day cycles
    2. Oligomenorrhea: Cycle greater than 35 day cycles (>45 days in adolescents)
    3. Metrorrhagia: Irregularly frequent Menses
  3. Quantifying Menstrual Bleeding amount
    1. Regular-absorbency tampons hold 6 to 9 grams (20 ml) of menstrual blood
    2. Super-absorbency tampons hold 9 to 12 grams (30 ml) of menstrual blood
    3. Heavy or Ultra Pads hold 30 to 50 ml of menstrual blood
    4. Menstrual Discs hold 60 to 80 ml of menstrual blood
    5. Menstrual Cups hold 20 to 35 ml of menstrual blood
    6. Menstrual underwear holds only 1-3 ml of menstrual blood
    7. DeLoughery (2024) BMJ Sex Reprod Health 50(1):21-6 +PMID: 37550075 [PubMed]
  4. Abnormal Menstrual Flow
    1. Menorrhagia (Hypermenorrhea)
      1. Over 80 cc blood loss per cycle
      2. Change pad or tampon every 1-2 hours
      3. Blood clots >1 inch (2.5 cm)
      4. More than 7 days of menstrual flow
    2. Menometrorrhagia (Metrorrhagia and Menorrhagia)
      1. Prolonged, irregularly frequent, heavy Menses
  5. Dysfunctional Uterine Bleeding
    1. Excessive, prolonged, or irregular uterine bleeding
  • Physiology
  • Ages of Menstrual Landmarks
  1. Thelarche: (10.2 to 11.3 years)
    1. See Tanner Girls Breast Development Stage
    2. Onset of secondary Breast development (marks the start of Puberty)
    3. Precedes Menarche by 24 months
  2. Menarche: 12.8 years (9.1 to 17.7 years)
    1. Precedes regular Menses by 12 months
    2. Anovulatory Cycles predominate initially
      1. Years 1 to 2 after Menarche: 55-85% of cycles
      2. Years 3 to 4 after Menarche: 30-50% of cycles
      3. Years 5 to 6 after Menarche: <20% of cycles
  3. Menopause: 51.4 years (48 to 55 years)