Abnormal Uterine Bleeding (AUB)

Causes, Workup and Treatment 


Before we launch into the topic of abnormal bleeding, it would be very helpful to review Menstrual Cycle 101.

To diagnose AUB you must understand the 

definitions of normal uterine bleeding:


normal duration = number of days of menstrual flow

normal duration = 3 - 7 days, usually 5


normal interval = 21 - 35 days, usually 28 

interval is the number of days between the 

first day of one period and the first day of the next.


Menorrhagia = heavy menstrual bleeding is

defined as menstrual blood loss greater than 80 ml per period. 

Metrorrhagia = bleeding between periods 


Causes of abnormal uterine bleeding:

hormone problems - click here to learn more. 

anatomic problems- click here to learn more. 



Workup of AUB: 

The workup of abnormal uterine bleeding reflects a search for the possible causes discussed above. 

1. We check bloodwork for certain hormone levels. And since up to 20 % of women presenting with heavy menstrual bleeding will have an underlying bleeding disorder, (1) we sometimes check for coagulation problems. 

2. To check for abnormal cells in the uterus, we do an endometrial biopsy (EMB). Click here to learn more. 

3.  Finally we check a Saline infusion Sonogram (SIS) to see not only the outside of the uterus, but the inner lining as well. This is to look for any structural abnormalities such as polyps or fibroids. 

Summary: Bloodwork, EMB and SIS


Treatment of AUB: 

Treatment can either be medical or surgical. Click here to learn more. 


(1) The American College of Obstetricians and Gynecologists Practice Bulletin number 128 July 2012, Diagnosis of Abnormal Uterine Bleeding in Reproductive-Aged Women