What is amenorrhea?

Causes and Symptoms

Amenorrhea, or the absence of menses, can be physiologic, such as during pregnancy, or pathologic. Amenorrhea can be primary or secondary in nature. Primary amenorrhea is defined as the absence of menses by age sixteen, even in the presence of normal growth and secondary sexual characteristics. In girls with abnormal growth, primary amenorrhea is defined as the absence of menses by age fourteen. Causes of primary amenorrhea include abnormalities of the reproductive outflow tract that prevent the flow of menstrual blood. Examples include imperforate hymen, transverse vaginal septum, and Asherman’s syndrome, whereby scar tissue within the uterus prevents the outflow of menstrual fluid. Girls with these conditions may experience cyclic cramping and discomfort from the buildup of menstrual blood. Other causes of primary amenorrhea include genetic problems such as Turner syndrome, in which the individual has a single X chromosome, or androgen insensitivity syndrome, in which the individual appears female but is genetically male and lacks ovaries and a uterus. Turner syndrome and androgen insensitivity tend to be asymptomatic regarding their amenorrhea. Rare congenital causes of primary amenorrhea include Kallman syndrome and empty sella syndrome.

Secondary amenorrhea refers to the absence of menstrual periods after menstrual cycles have occurred previously. It is defined as the absence of menses for the duration of three regular menstrual cycles or six months. Physiological causes of secondary amenorrhea include pregnancy, the postpartum state, and the menopause. Pathologic causes of secondary amenorrhea include disorders of the central nervous system or hypothalamus, such as extreme stress or exercise and anorexia nervosa. Disorders of the pituitary gland, such as tumors, can cause secondary amenorrhea as well. These tumors may be accompanied by galactorrhea, from high levels of prolactin, or by visual impairment. Hormonal disturbances can also lead to secondary amenorrhea. One example is hypothyroidism, which is often accompanied by fatigue and cold intolerance. Polycystic ovary syndrome, an endocrinologic disorder characterized by insulin resistance and
hirsutism, may also lead to amenorrhea. Another cause of secondary amenorrhea is premature ovarian failure,
which may be attributable to radiation or chemotherapy. These individuals may experience the symptoms of early menopause, such as hot flashes and vaginal dryness.

Treatment and Therapy

The treatment for amenorrhea depends on the cause. If the disorder is the result of anatomic causes, then surgery may cure it. For instance, an imperforate hymen or transverse vaginal septum can be corrected surgically, allowing for normal outflow of menstrual fluid. If the disorder is the result of hormonal imbalances, then medications may be given, such as thyroid hormone for hypothyroidism or bromocriptine for hyperprolactinemia. In individuals with polycystic ovary syndrome, metoformin may be given to regulate the menstrual cycles. By correcting these hormonal imbalances, the resumption of regular menstrual cycles may occur, thus allowing for conception and pregnancy, if the individual so desires.

In cases of amenorrhea caused by extreme stress or exercise and anorexia nervosa, removal from the stressful conditions, a decrease in exercise levels, or an increase in caloric intake to maintain normal ideal body weight often remediates amenorrhea. Individuals who suffer from anorexia nervosa also require psychiatric treatment.

Individuals with genetic causes or premature ovarian failure leading to amenorrhea are unlikely to attain menstruation via medical therapy. For these individuals, therapy is aimed at preventing or treating the sequelae of estrogen deficiency that accompany amenorrhea. For instance, women with premature ovarian failure are at risk for the depletion of bone mineral density and osteoporosis. These individuals may benefit from hormone therapy in the form of estrogen and progesterone.

Perspective and Prospects

The cause for amenorrhea can often be found, since a vast array of diagnostic tests are available. Anatomic abnormalities may be detected on physical examination or via imaging of the reproductive structures such as ultrasound. Hormonal causes of amenorrhea can often be found through blood tests of hormones produced by the hypothalamus, pituitary gland, ovaries, thyroid gland, and adrenal glands. These tests can identify the hormone derangement and which organ is responsible. Genetic tests have allowed physicians to understand the basis of primary amenorrhea on a molecular level. While many cases of amenorrhea can be treated effectively once the cause has been identified, the future holds promise that better therapies with fewer side effects will be found.

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Vorvick, Linda J., and David Zieve. "Amenorrhea - Primary." MedlinePlus, May 31, 2012.

Vorvick, Linda J., and David Zieve. "Secondary Amenorrhea." MedlinePlus, May 31, 2012.