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What are menstrual irregularities?

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After a teen has been menstruating for a few years, her menstrual cycle typically becomes more regular. For most women, a normal menstrual cycle ranges from 21 to 35 days.1 However, up to 14% of women have irregular menstrual cycles or excessively heavy menstrual bleeding. Most abnormal uterine bleeding can be divided into anovulatory and ovulatory patterns.2

  • Anovulatory: Irregular/infrequent periods with absent, minimal, or excessive bleeding.2
  • Ovulatory: Periods that occur at regular intervals but are characterized by excessive bleeding or a duration of greater than 7 days.2

The most common menstrual irregularities include:

Anovulatory Bleeding

  • Absent menstrual periods (amenorrhea, pronounced ey-men-uh-REE-uh):2,3,4,5 When a woman does not get her period by age 16, or when she stops getting her period for at least 3 months and is not pregnant.
  • Infrequent menstrual periods (oligomenorrhea, ol-i-goh-men-uh-REE-uh): Periods that occur more than 35 days apart.3

Ovulatory Bleeding

  • Heavy menstrual periods (menorrhagia, pronounced men-uh-REY-jee-uh):2,3,6 Also called excessive bleeding. Although anovulatory bleeding and menorrhagia are sometimes grouped together, they do not have the same cause and require different diagnostic testing.6
  • Prolonged menstrual bleeding: Bleeding that exceeds 8 days in duration on a regular basis.3

Dysmenorrhea (pronounced dis-men-uh-REE- uh): Painful periods that may include severe menstrual cramps.7

Additional menstrual irregularities include:

  • Polymenorrhea (pronounced pol-ee-men-uh-REE-uh): Frequent menstrual periods occurring less than 21 days apart3
  • Irregular menstrual periods with a cycle-to-cycle variation of more than 20 days3
  • Shortened menstrual bleeding of less than 2 days in duration3
  • Intermenstrual bleeding: Episodes of bleeding that occur between periods, also known as spotting3

  1. American College of Obstetricians and Gynecologists (ACOG). (2011). Menstruation FAQ. Retrieved from External Web Site Policy (PDF - 464 KB) [top]
  2. Sweet, M. G., Schmidt-Dalton, T. A., Weiss, P. M., & Madsen, K. P. (2012). Evaluation and management of abnormal uterine bleeding in premenopausal women. American Family Physician, 85, 35-43. [top]
  3. Munro, M. G., Critchley, H. O., & Fraser, I. S. (2012). The FIGO systems for nomenclature and classification of causes of abnormal uterine bleeding in the reproductive years: Who needs them? American Journal of Obstetrics and Gynecology. doi: 10.1016/j.ajog.2012.01.046 [top]
  4. Master-Hunter, T., & Heiman, D. L. (2006). Amenorrhea: Evaluation and treatment. American Family Physician, 73, 1374-1382. [top]
  5. Practice Committee of the American Society for Reproductive Medicine. (2008). Current evaluation of amenorrhea. Fertility and Sterility, 90, S219-225. doi: 10.1016/j.fertnstert.2008.08.038 [top]
  6. Apgar, B. S., Kaufman, A. H., George-Nwogu, U., & Kittendorf, A. (2007). Treatment of menorrhagia. American Family Physician, 75, 1813-1819. [top]
  7. French, L. (2005). Dysmenorrhea. American Family Physician, 71, 285-291. [top]

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