This document discusses menstrual disorders and provides information about normal menstrual cycles as well as common disorders. It describes that a normal menstrual cycle is typically between 20-40 days with bleeding lasting 2-7 days and average blood loss of 40cc. Common symptoms include cramps and feelings of unpleasantness due to hormonal withdrawal. Main disorders discussed are premenstrual syndrome (PMS), abnormal menstruation, and dysfunctional uterine bleeding (DUB). PMS occurs in the 4-5 days before a period due to water and electrolyte imbalance from estrogen. Abnormal menstruation encompasses conditions like menorrhagia and metrorrhagia. DUB results in excessive bleeding that is irregular in duration, amount and frequency