What causes menstrual irregularities?

Menstrual irregularities can have a variety of causes, including pregnancy, hormonal imbalances, infections, diseases, trauma, and certain medications.1,2,3,4,5,6

Causes of irregular periods (generally light) include:2

  • What causes your period to be irregular?Perimenopause (generally in the late 40s and early 50s)
  • Primary ovarian insufficiency (POI)
  • Eating disorders (anorexia nervosa or bulimia)
  • Excessive exercise
  • Thyroid dysfunction (too much or too little thyroid hormone)
  • Elevated levels of the hormone prolactin, which is made by the pituitary gland to help the body produce milk
  • Uncontrolled diabetes 
  • Cushing's syndrome (elevated levels of the hormone cortisol, used in the body's response to stress)
  • Late-onset congenital adrenal hyperplasia (problem with the adrenal gland)
  • Hormonal birth control (birth control pills, injections, or implants)
  • Hormone-containing intrauterine devices (IUDs)
  • Scarring within the uterine cavity (Asherman's syndrome)
  • Medications, such as those to treat epilepsy or mental health problems

Common causes of heavy or prolonged menstrual bleeding include:2,7

  • Adolescence (during which cycles may not be associated with ovulation)
  • Polycystic ovary syndrome (PCOS) (bleeding irregular but heavy)
  • Uterine fibroids (benign growths of uterine muscle)
  • Endometrial polyps (benign overgrowth of the lining of the uterus)
  • Adenomyosis (the presence of uterine lining in the wall of the uterus)
  • Nonhormonal IUDs
  • Bleeding disorders, such as leukemia, platelet disorders, clotting factor deficiencies, or (less common) von Willebrand disease
  • Pregnancy complications (miscarriage)

Common causes of dysmenorrhea (menstrual pain) include:6,9


  1. American College of Obstetricians and Gynecologists (ACOG). (2012). FAQ: Abnormal uterine bleeding. Retrieved on May 24, 2016, from http://www.acog.org/Patients/FAQs/Abnormal-Uterine-Bleeding External Web Site Policy (PDF - 464 KB)
  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.
  3. Master-Hunter, T., & Heiman, D. L. (2006). Amenorrhea: Evaluation and treatment. American Family Physician, 73, 1374–1382.
  4. Apgar, B. S., Kaufman, A. H., George-Nwogu, U., & Kittendorf, A. (2007). Treatment of menorrhagia. American Family Physician, 75, 1813–1819.
  5. Practice Committee of the American Society for Reproductive Medicine. (2008). Current evaluation of amenorrhea [Review]. Fertility and Sterility, 90, S219–S225.
  6. French, L. (2005). Dysmenorrhea. American Family Physician, 71, 285–291.
  7. Godfrey, E. M., Folger, S. G., Jeng, G., Jamieson, D. J., & Curtis, K. M. (2013). Treatment of bleeding irregularities in women with copper-containing IUDs: A systematic review. Contraception, 87(5), 549–566. Retrieved August 2, 2016, from http://www.contraceptionjournal.org/article/S0010-7824(12)00816-5/abstract External Web Site Policy
  8. Centers for Disease Control and Prevention. (2016). Chlamydia—CDC fact sheet. Retrieved on August 2, 2016, from http://www.cdc.gov/std/chlamydia/stdfact-chlamydia.htm
  9. American College of Obstetricians and Gynecologists. (2016). FAQ: Gonorrhea, chlamydia, and syphilis. Retrieved on August 2, 2016, from http://www.acog.org/Patients/FAQs/Gonorrhea-Chlamydia-and-Syphilis External Web Site Policy

What are the symptoms of menstruation?

What are menstrual problems or irregularities?

How many women are affected by menstrual irregularities?

What causes menstrual irregularities?

How do health care providers diagnose menstrual irregularities?

What are the common treatments for menstrual irregularities?

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