Decreased or absent secretion of hormones from the gonads. The gonads refer to both sex glands: the female ovaries and the male testes.
Causes, incidence, and risk factors
The cause of hypogonadism may be "primary" or "central." In primary hypogonadism, the ovaries or testes themselves do not function properly. Some causes include surgery, radiation, genetic and developmental disorders, infection, and liver and kidney disease. The most common genetic disorders are Turner's syndrome (in women) and Klinefelter's (in men). In central hypogonadism, brain glands that control the gonads do not function properly. These brain glands are called the pituitary and hypothalamus. Some causes of central hypogonadism include tumors (growths), surgery and radiation, infections and inflammation, trauma, bleeding, genetic problems, nutritional deficiency, and iron excess (hemochromatosis). A genetic cause of central hypogonadism along with lack of smell is Kallmann's syndrome (males). The most tumors affecting the pituitary area are craniopharyngioma (children) and prolactinoma (adults; excess milk-producing hormone). Prolactinomas cause hypogonadism even if they are not large.
Signs and tests
Tests are done for levels of estrogen (women) and testosterone (men) as well as FSH and LH, the pituitary hormones that stimulate the gonads. Other tests may include a thyroid level, sperm count, prolactin level (milk hormone), blood tests for anemia and chemistries, iron, or genetic analysis. Sometimes imaging, such as a sonogram of the ovaries, is necessary. If pituitary disease is suspected, an MRI or CT scan of the brain may be done.
Treatment
Hormonal preparations are available for men and women. Estrogen comes as a patch and pill. Testosterone can be given as a patch or injection. If there is a correctible cause of hypogonadism (e.g. pituitary tumor), medication may be given (particularly for prolactinoma) or surgery/radiation be done. Injections or oral medication can be used to stimulate ovulation. Therapy may also target nutritional, infectious or other causes of the problem.
Expectations (prognosis)
Many forms of hypogonadism are potentially treatable and have a good prognosis.
Complications
In women, hypogonadism may cause infertility. Menopause is a form of naturally occurring hypogonadism, but many women complain of hot flashes, vaginal dryness, and irritability. The risk of osteoporosis and heart disease increase after menopause or when estrogen levels are low. Some women opt to take estrogen therapy; this particularly applies to women who have an early menopause ("premature ovarian failure"). In men, hypogonadism results in loss of libido and may cause weakness, impotence, infertility and osteoporosis. Men also experience some decline in testosterone as they age, but not as much as women do.
Calling your health care provider
Consult with your doctor if you notice loss of menses, breast discharge, inability to conceive, hot flashes (women), impotence, loss of body hair, weakness or breast enlargement (men). Both men and women should call if headaches or visual problems occur.
Prevention
You should be careful not to diet and exercise too strenuously and to try to maintain normal body weight and healthy eating. Those with low levels of gonadal hormones should discuss with their doctor whether replacement therapy is appropriate.