Applied Evidence

A systematic approach to chronic abnormal uterine bleeding

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The care you provide to women of childbearing age who are bleeding gets an assist from an established classification system of 9 causes and a range of therapies.


› Perform endometrial biopsy on all women who have abnormal uterine bleeding and risk factors for endometrial cancer and on all women ≥45 years, regardless of risk. C

› Initiate a workup for a coagulation disorder in women who are close to the onset of menarche and have a history of heavy menstrual bleeding. C

› Promote lifestyle changes and weight loss as primary treatments for polycystic ovary syndrome. B

Strength of recommendation (SOR)

A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series



Menstrual bleeding is considered normal when it occurs regularly (every 21-35 days), lasts 4 to 8 days, and is not associated with heavy bleeding.1 During the first few years after menarche, it is normal for girls to experience irregular menstrual cycles but, by the third year, 60% to 80% of girls have an adult pattern of menstrual bleeding.2

Menstrual flow without normal volume, duration, regularity, or frequency is considered abnormal uterine bleeding (AUB). The condition is considered acute if there is need for immediate intervention. In the absence of the need for immediate intervention, recurrent AUB is classified as chronic.3 Chronic AUB is the focus of this article.

FIGO classification of  abnormal uterine bleeding

Invaluable tool: The FIGO classification

In 2011, the International Federation of Gynecology and Obstetrics (FIGO) proposed what is known as the PALM–COEIN AUB classification system (TABLE 1).3 This mnemonic system divides AUB into 2 broad types:

  • structural causes, recalled by “PALM” (Polyps, Adenomyosis, Leiomyoma, and Malignancy/hyperplasia)
  • nonstructural causes, recalled by “COEIN” (Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic, and Not yet classified).
A guide to working up, and differentiating, abnormal uterine bleeding
A guide to working up, and differentiating, abnormal uterine bleeding

The PALM–COEIN system also uses descriptive terminology (heavy bleeding, intermenstrual bleeding) to characterize the bleeding pattern.3 The American College of Obstetricians and Gynecologists has adopted this classification system and recommends that such historically used terminology as “dysfunctional uterine bleeding,” “menorrhagia,” and “metrorrhagia” be abandoned.1

Workup of abnormal uterine bleeding in women <18 years

The initial workup of all causes of chronic uterine bleeding begins with a history; physical examination, including pelvic exam; and laboratory testing, including a urine pregnancy test, complete blood count, and a test of thyroid-stimulating hormone (TABLE 2). The need for additional laboratory testing, imaging, or endometrial biopsy depends on the suspected cause of AUB, detailed stepwise in FIGURE 1 (women <18 years) and FIGURE 2 (≥18 years).

Workup of abnormal uterine bleeding in women ≥18 years

We first briefly review the 9 categories of AUB in the PALM–COEIN system; discuss the most common causes in more detail; and review common treatment options (TABLE 3).

Which medical therapies for which subtypes of abnormal uterine bleeding?


Marsha R, a 41-year-old-woman, complains of heavy menstrual bleeding for the past year that has become worse over the past 2 months. Her menstrual cycles have occurred every 28 days and last 10 days; she uses 10 to 12 pads a day.

Continue to: Recently, Ms. R reports...


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