Menstruation

Menstruation is the term applied to the discharge of blood which issues every month from the generative organs of the human female during the period in which she is capable of procreation. The first appearance of this discharge, to which the terms menses and catamenia (each having reference to the monthly period) are indiscriminately applied, is a decided indication of the arrival of the period of commencing womanhood, and is usually accompanied by an enlargement of the mammary glands and other less conspicuous changes. Among Teutonic races menstruation usually commences between the fourteenth and the sixteenth years, and terminates between the forty-eighth and fifty-second years. The interval which most commonly elapses between the successive appearances of the discharge is about four weeks, although it is often shorter; and the duration of the flow is usually three or four days, but is liable to great variations. The first appearance of the discharge is usually preceded and accompanied by pain in the loins and general disturbance of the system, and in many women these symptoms invariably accompany the discharge. As a general rule there is no menstrual flow during pregnancy and lactation, and its cessation is one of the first signs that conception has taken place. Anomalies and disturbances (retention, suppression, undue copiousness, &c.) of the menstrual discharge are a frequent cause or symptom of illness.