Amenorrhea

Amenorrhea or amenorrhoea is the absence of a menstrual period in a female who has reached reproductive age.^[1] Physiological states of amenorrhoea are most commonly seen during pregnancy and lactation (breastfeeding).^[1]

Amenorrhoea is a symptom with many potential causes.^[2] Primary amenorrhea is defined as an absence of secondary sexual characteristics by age 13 with no menarche or normal secondary sexual characteristics but no menarche by 15 years of age.^[3] It may be caused by developmental problems, such as the congenital absence of the uterus, failure of the ovary to receive or maintain egg cells, or delay in pubertal development.^[4] Secondary amenorrhoea, ceasing of menstrual cycles after menarche, is defined as the absence of menses for three months in a woman with previously normal menstruation, or six months for women with a history of oligomenorrhoea.^[3] It is often caused by hormonal disturbances from the hypothalamus and the pituitary gland, premature menopause, intrauterine scar formation, or eating disorders.^[5][6][7]