Menstrual synchrony by chance when there is menstrual cycle variability. Yang and Schank argued that when there is cycle variability (i.e., either women have irregular cycles, have cycles of different frequencies, or both), most women will have the opportunity to experience synchrony even though it is a result of cycle variability and not a result of a mechanism such as the exchange of pheromones. For example, consider two women A and B. Suppose A has menstrual cycles that are 28 days long and B has cycles that are 30 days long. Suppose further that when A and B become close friends, B
Heavy menstrual bleeding whose symptoms are not well-controlled. Approximately 53 in 1000 women are affected by AUB. A normal menstrual cycle is 21–35 days in duration, with bleeding lasting an average of 5 days and total blood flow between 25 and 80 mL. Heavy menstrual bleeding is defined as total menstrual flow >80ml per cycle, or soaking a pad/tampon every 2 hours or less. Deviations in terms of frequency of menses, duration of menses, or volume of menses qualifies as abnormal uterine bleeding. Bleeding in between menses is also abnormal uterine bleeding and thus requires further evaluation. Complications of heavy menstrual bleeding could