How does amenorrhea develop?
There are two types of amenorrhea—primary and secondary. Primary amenorrhea occurs when a woman has not had her first menstrual period by age 16. This is most often due to late puberty, and fairly common among teenage girls who are either very thin or very athletic, and who as a result have abnormally low body fat. In other girls, the delay of menses may be due to Turner’s syndrome, a genetic disorder involving the sex chromosomes, or to a developmental abnormality of the female reproductive organs. Secondary amenorrhea occurs when a woman who has menstruated previously fails to menstruate for six consecutive months in the absence of normal causes such as pregnancy, lactation and menopause. The levels of female reproductive hormones in amenorrheic women are not sufficient to stimulate menstruation. This condition is sometimes associated with malnutrition, such as that which occurs with anorexia nervosa, or with extreme exercise, which puts excessive nutritional as well as other demands
