From Encyclopedia of Sex and Sexuality
Women’s menstrual cycles involve an extremely complex and interrelated series of physiological mechanisms; the failure of any of these can cause amenorrhea, the cessation of menstruation. The principal organs involved in menstruation—the brain, ovaries, uterus, and fallopian tubes—are activated by various chemical messengers, or hormones: follicle stimulating hormone, estrogen, luteinizing hormone, and progesterone.
Two types of amenorrhea are clinically recognized: primary amenorrhea, or the failure to begin menstruating when the woman has reached the level of maturity at which it can otherwise be expected; and secondary amenorrhea, or the loss of menstruation after a woman’s menstrual cycles have begun. There are three fundamental causes of amenorrhea: first, of course, is the possibility that the woman may be pregnant; second, there is a possibility that one of the organs involved in the cycle is missing or not functioning properly, causing primary amenorrhea; the third, and by far the most common cause, is the absence of specific hormones or the failure of the proper hormones to function properly. Hormonal problems generally stem from the failure of the ovaries to produce the required estrogen and progesterone. In some cases an excess of male hormones is produced instead of the proper amount of female hormones. Amenorrhea and a certain degree of masculinization results, and symptoms may include excess facial hair, acne, and a deepening of the voice. Other causes of amenorrhea include cysts or tumors, stress, disease, and occasionally the emotional problems of adolescence. Anorexics and women who exercise rigorously—runners in training, for example—can also experience a loss of menstruation. Finally, amenorrhea appears at the onset of menopause, the cessation of menstruation in women whose childbearing years have ended.
The treatment of amenorrhea is determined by the precise cause of the individual case. X-rays and blood tests are often useful in determining the cause. As mentioned above, the most common cause of primary amenorrhea is the absence or failure of hormones. Hormone treatment is, therefore, generally successful in initiating menstruation, and is given in the form of oral medication, often in a similar formula to that of the oral contraceptive pill. On the rare occasion of finding an imperforate hymen or other anatomical abnormalities, surgical intervention will be necessary.
The most common cause of secondary amenorrhea among adolescents is stress and a change in life circumstances. It is often found in students, who leave home to live in dorms. In most cases, reassurances and sometimes a simple change in life-style may be all that is needed to relieve stress and resume menstruation.