At the onset of puberty, hormone fluctuations lead to ovary maturation, which marks the beginning of menstruation. For the length of a woman's fertile life, hormones released within the brain and by the ovaries circulate throughout the body to facilitate egg maturation and release from the ovary, the thickening of the uterine lining, and the shedding of the lining during menstruation. Missed or absent periods may indicate the presence of an underlying disease or disorder that requires medical attention.
Polycystic Ovarian Disease
A common cause of missed or absent periods is polycystic ovarian disease, also called PCOS. Patients with PCOS suffer from a hormone imbalance characterized by abnormal estrogen, progesterone and testosterone levels. Under normal conditions, estrogen and progesterone signal for the maturation of an egg within a sac, called a cyst, and the subsequent release of the egg from the cyst, each menstrual cycle. In polycystic ovary disease, hormone disruptions prevent normal egg release, so a cyst remains on the ovary. Over time, a number of cysts develop on the ovaries. Women with PCOS suffer from a number of symptoms, including irregular or absent periods, infertility, obesity, insulin resistance and diabetes, male pattern baldness and excess body hair growth, reports the University of Chicago Medical Center. Although PCOS is incurable, hormone therapies can help regulate hormone levels and restore proper menstruation.
Excessive Exercise
Excessive exercise and physical activity can also lead to missed and irregular periods. Women without sufficient body fat as a result of diet and exercise do not typically ovulate, and may miss periods for months at a time. Exercise itself also directly causes missed periods by affecting a structure in the brain called the hypothalamus. The hypothalamus acts as a hormone control signal within the brain, and controls the release of a number of hormones related to menstruation. Excessive exercise places the body under stress and leads to the release of cortisol, a stress hormone. Consistently high levels of cortisol prevent proper hypothalamic function, leading to hormone imbalances that cause missed periods, according to Georgia Reproductive Specialists. Patients suffering from missed periods should discuss exercise habits with their doctor.
Autoimmune Disorders
In some causes, autoimmune diseases can lead to skipped or absent periods, according to Endotext.org. Some autoimmune diseases attack hormone glands throughout the body, such as the adrenal glands located on top of the kidneys or the thyroid gland. Damage to hormone-releasing glands can lead to insufficient production of ovary-stimulating hormones, leading to ovarian failure. Patients with autoimmune disorders often have increased blood antibody levels, corresponding to over-activity of the immune system. Often, therapy to supplement low hormone levels can restore proper ovarian function.
