Hormone Testing for Men: 10 Common Lab Tests

DHEA-sulfate test measures the amount of DHEA-sulfate in the blood. DHEA-sulfate is a weak male hormone (androgen) produced by the adrenal gland in both men and women.

Estradiol (estradiol-17 beta, E2) is part of an estrogen that is a group of steroids that regulate the menstrual cycle and function as the main female sex hormones. Estrogens are responsible for the development of female sex organs and secondary sex characteristics and are tied to the menstrual cycle and pregnancy. They are considered the main sex hormones in women and are present in small quantities in men. Estradiol (E2) is the predominant form of estrogen and is produced primarily in the ovaries with additional amounts produced by the adrenal glands in women and in the testes and adrenal glands in men. Estradiol levels are used in evaluating ovarian function. Estradiol levels are increased in cases of early (precocious) puberty in girls and gynecomastia in men. Its main use has been in the differential diagnosis of amenorrhea – for example, to determine whether the cause is menopause, pregnancy, or a medical problem. In assisted reproductive technology (ART), serial measurements are used to monitor follicle development in the ovary in the days prior to in vitro fertilization. Estradiol is also sometimes used to monitor menopausal hormone replacement therapy.

The insulin-like growth factor-1 (IGF-1) test is an indirect measure of the average amount of growth hormone (GH) being produced by the body. IGF-1 and GH are polypeptide hormones, small proteins that are vital for normal bone and tissue growth and development. GH is produced by the pituitary gland, a grape-sized gland located at the base of the brain behind the bridge of your nose. GH is secreted into the bloodstream in pulses throughout the day and night with peaks that occur mostly during the night. IGF-1 is produced by the liver and skeletal muscle as well as many other tissues in response to GH stimulation. IGF-1 mediates many of the actions of GH, stimulating the growth of bones and other tissues and promoting the production of lean muscle mass. IGF-1 mirrors GH excesses and deficiencies, but its level is stable throughout the day, making it a useful indicator of average GH levels.

z Score. A z-score (aka, a standard score) indicates how many standard deviations an element is from the mean. A z-score can be calculated from the following formula. z = (X - µ) / s where z is the z-score, X is the value of the element, µ is the population mean, and s is the standard deviation.

Prolactin is a hormone produced by the anterior portion of the pituitary gland, a grape-sized organ found at the base of the brain. Prolactin secretion is regulated and inhibited by the brain chemical dopamine. Normally present in low amounts in men and non-pregnant women, prolactin's primary role is to promote lactation (breast milk production). Prolactin levels are usually high throughout pregnancy and just after childbirth. During pregnancy, the hormones prolactin, estrogen, and progesterone stimulate breast milk development. Following childbirth, prolactin helps initiate and maintain the breast milk supply. If a woman does not breastfeed, her prolactin level soon drops back to pre-pregnancy levels. If she does nurse, suckling by the infant plays an important role in the release of prolactin. There is a feedback mechanism between how often the baby nurses and the amount of prolactin secreted by the pituitary as well as the amount of milk produced. Another common cause of elevated prolactin levels is a prolactinoma, a prolactin-producing tumor of the pituitary gland. Prolactinomas are the most common type of pituitary tumor and are usually benign. They develop more frequently in women but are also found in men. Problems resulting from them can arise both from the unintended effects of excess prolactin, such as milk production in the non-pregnant woman (and rarely, man) and from the size and location of the tumor. If the anterior pituitary gland and/or the tumor enlarge significantly, it can put pressure on the optic nerve, causing headaches and visual disturbances, and it can interfere with the other hormones that the pituitary gland produces. In women, prolactinomas can cause infertility and irregularities in menstruation; in men, these tumors can cause a gradual loss in sexual function and libido. If left untreated, prolactinomas may eventually damage the tissues around them.

In many cases, measurement of total testosterone provides the doctor with adequate information. However, in certain cases, for example when the level of SHBG is abnormal, a test for free or bioavailable testosterone may be performed as it may more accurately reflect the presence of a medical condition.

The sex hormone binding globulin (SHBG) test measures the concentration of SHBG in the blood. SHBG is a protein that is produced by the liver and binds tightly to testosterone, dihydrotestosterone (DHT), and estradiol (an estrogen). In this bound state, it transports them in the blood as an inactive form. The amount of SHBG in circulation is affected by age and sex, by decreased or increased testosterone or estrogen production and can be affected by certain diseases and conditions such as liver disease, hyperthyroidism or hypothyroidism, and obesity. Changes in SHBG levels can affect the amount of testosterone that is available to be used by the body's tissues. A total testosterone test does not distinguish between bound and unbound testosterone but determines the overall quantity of testosterone. If a person's SHBG level is not normal, then the total testosterone may not be an accurate representation of the amount of testosterone that is available to the person's tissues.

A testosterone test measures the amount of the male hormone, testosterone, in the blood. Both men and women produce this hormone. In males, the testicles produce most of the testosterone in the body. Levels are most often checked to evaluate signs of low testosterone: In boys -- early or late puberty and in men -- impotence, low level of sexual interest, infertility, thinning of the bones In females, the ovaries produce most of the testosterone and levels are most often checked to evaluate signs of higher testosterone levels, such as: decreased breast size, excess hair growth, increased size of the clitoris. irregular or absent menstrual periods and male-pattern baldness or hair thinning.