Cessation of menstruation, normally occurring between the ages of 40 and 55 (the menopause), but sometimes at an early age, especially as a result of severe under-nutrition (as in anorexia nervosa) when body weight falls below about 45 kg.
Absence of menstruation.
The absence of one or more menstrual periods, usual during pregnancy and after the menopause.
Absence of menstruation at the time of life at which it should normally occur. If menstruation has never occurred, the amenorrhoea is termed primary; secondary amenorrhoea is defined as menstruation ceasing after a normal cycle has been experienced for a number of years.
Amenorrhea refers to the absence of menstrual periods. Primary amenorrhea is characterized by the failure to initiate menstruation by the age of 16. On the other hand, secondary amenorrhea pertains to the temporary or permanent cessation of periods in women who have previously experienced regular menstrual cycles.
The primary cause of primary amenorrhea is often attributed to the delayed onset of puberty. While such delays may not necessarily indicate a disorder, in rare instances, they can result from endocrine system disorders, such as pituitary tumors, hypothyroidism (underactivity of the thyroid gland), adrenal tumors, or adrenal hyperplasia. Turner’s syndrome, a condition where one female sex chromosome is missing, is another uncommon cause of delayed puberty. In some cases, the absence of menstruation can be attributed to the absence of the vagina or uterus since birth. It may also occur if there is no perforation in the hymen (the membrane across the opening of the vagina), preventing the escape of menstrual blood.
The most frequent cause of temporary secondary amenorrhea is pregnancy. Additionally, hormonal changes resulting from factors like stress, depression, anorexia nervosa, certain medications, or disorders of the pituitary gland or thyroid can also lead to secondary amenorrhea. Another potential cause is an ovarian disorder, such as polycystic ovary syndrome or an ovarian tumor. Permanent amenorrhea occurs after menopause or following a hysterectomy, which is a surgical procedure to remove the uterus.
Investigation of amenorrhea typically involves a physical examination and blood tests to assess hormone levels. In order to rule out the possibility of a pituitary tumor, CT scanning or MRI techniques, which produce three-dimensional or cross-sectional images, may be conducted on the skull. Ultrasound scanning of the abdomen and pelvis can be performed to exclude the presence of adrenal gland or ovarian tumors. In some cases, laparoscopy, which involves examining the inside of the abdomen using a rigid or flexible viewing tube, may be necessary to assess the condition of the ovaries.
If treatment for amenorrhea is deemed necessary, it primarily focuses on addressing the underlying cause of the condition.