Menstrual cycles have wide variability (Griswold, 2004). The complete absence of menses is called amenorrhea. While the nomenclature for irregular or abnormal menstrual cycles has changed to the more simplified abnormal uterine bleeding, many still use the following terminology. Menses that occur infrequently, at intervals greater than 35 days, are labeled as oligomenorrhea. The opposite extreme, menses at intervals of 21 to 24 days or fewer, is known as polymenorrhea. When regular bleeding is excessive in duration and flow (greater than 80 mL/cycle or lasting longer than 7 days), it is defined as hypermenorrhea or menorrhagia. Metrorrhagia describes irregularly occurring bleeding that is excessive in flow and length. Irregular, heavy bleeding is called menometrorrhagia. Hypomenorrhea is regular bleeding in less than the normal amount. Bleeding at any time between otherwise normal menses is defined as intermenstrual bleeding.