Adrenarche takes place in girls between 5 and 6 years of age and in boys between 8 and 9 years of age. It is responsible for the first measurable changes in reproductive hormone levels. The subsequent increase in DHEA and DHEAS is followed by a rise in androstenedione concentrations one to two years later.
Loss of terminal hair, most commonly on the head, resulting in male-pattern baldness or complete baldness
The absence of menses in a woman of reproductive age. Primary amenorrhea results from damage to or absence of the uterus, while secondary amenorrhea results from hormonal dysfunction or imbalance at the hypothalamic, pituitary or ovarian level. Secondary amenorrhea is generally associated with anovulation. Nonpathological amenorrhea occurs during pregnancy and lactation.
Any of the steroid hormones whose primary function is the development and maintenance of male sex characteristics and reproductive abilities. Androgens include testosterone, DHEAS, androstenedione, androsterone, androstenilone and dihydrotestosterone (DHT). Low levels of androgens are also vital to female physiology.
Complete or partial inability to utilize testosterone because of a defect in the nuclear androgen receptor. Incomplete resistance underlies a range of developmental defects in sexual differentiation resulting in a variety of intersex phenotypes. Complete resistance results in testicular feminization.
Andropause, or male menopause, refers to a menopause-like condition in middle-aged men. This may relate to a reduction of the production of testosterone and DHEAS.
Bioavailable testosterone (BAT)
The fraction of total testosterone available for physiological use.
BAT = Free Testosterone + Albumin-bound Testosterone
Calculated free testosterone (cFT)
An index of bioavailable testosterone. Calculation includes the concentrations of circulating testosterone, SHBG and albumin, and the association constants for SHBG and albumin.
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Any of several steroid hormones derived from testosterone whose primary function is the control of female sexual differentiation, development, and reproductive ability. The primary estrogens are estrone, estradiol, and estriol. Low levels of estrogens are also involved in male physiology.
Free androgen index (FAI)
An index of free testosterone (testosterone not bound to SHBG) calculated by the equation:
100 x [TT] / [SHBG]
Where TT = total testosterone and the level of SHBG is determined by immunoassay. Both TT and SHBG are expressed in nmol/L.
The circulating fraction of testosterone that is not bound by any carrier protein.
Gonadarche refers to the earliest gonadal changes of puberty. In response to pituitary gonadotropins, the ovaries in girls and the testes in boys begin to grow and increase the production of sex steroids, especially estradiol and testosterone.
Human Chorionic Gonadotropin (hCG)
A hormone produced by trophoblastic tissue that normally stimulates the production of progesterone for the maintenance of early pregnancy.
Usually caused by abnormally high levels of male hormones (androgens), hirsutism is the excessive growth of thick dark hair in locations where hair growth in women is usually minimal or absent. Such male-pattern growth of terminal body hair usually occurs in androgen-stimulated locations, such as the face and chest.
Abnormally high levels of androgens, usually as evidenced by testosterone levels.
A clinical condition related to or caused by excessive amounts of gonadotropins.
The presence of abnormally high levels of prolactin in the blood. Prolactin is a peptide hormone produced by the pituitary gland primarily associated with lactation and plays important breast development during pregnancy. Hyperprolactinemia may cause disruptions in the normal menstrual period in women and hypogonadism, infertility and erectile dysfunction in men.
The reduced or absent secretion of hormones from the testes (in men) or the ovaries (in women). Also known as Gonadal Deficiency.
Absent or decreased function of the male testes or the female ovaries. Possible complications include delayed puberty and infertility.
The normal cessation of menses and reproductive ability in aging women.
Normogonadotropic refers to delayed sexual development and growth delay. It occurs despite normal pituitary gonadotropin secretion.
Polycystic ovary syndrome
A (probably genetic) disorder resulting in some combination of hyperandrogenism, irregular or absent menses, multiple cysts in the ovaries, infertility and other metabolic disorders.
In women, refers to the reproductive years following puberty but prior to menopause.
Sex Hormone-Binding Globulin (SHBG)
A carrier protein in the blood that binds testosterone with high affinity, regulating its availability for cell uptake and usage.
The primary active steroid sex hormone in men.
The total concentration of circulating testosterone, both free and complexed with carrier proteins.
The development of male secondary sex characteristics in a woman, potentially including a deepening voice, increased body and/or facial hair, male-pattern baldness, and clitoral enlargement.