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
- 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
- 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 (PDF 464 KB)
- 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.
- Master-Hunter, T., & Heiman, D. L. (2006). Amenorrhea: Evaluation and treatment. American Family Physician, 73, 1374–1382.
- Apgar, B. S., Kaufman, A. H., George-Nwogu, U., & Kittendorf, A. (2007). Treatment of menorrhagia. American Family Physician, 75, 1813–1819.
- Practice Committee of the American Society for Reproductive Medicine. (2008). Current evaluation of amenorrhea [Review]. Fertility and Sterility, 90, S219–S225.
- French, L. (2005). Dysmenorrhea. American Family Physician, 71, 285–291.
- 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
- 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
- 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