TESTOSTERONE, TOTAL

LAB124

Green top/Gel Li Hep

2.0 mL

7 mL Red Top Tube

Refrigerate specimen

Set Up:Daily Report Available:1 day

Females: <=81 ng/dL Males: 280-800 ng/dL

Testosterone is required for masculine differentiation of the genital tract, and for the development and maintenance of male secondary sex characteristics, i.e. muscle bulk, bone mass, sex drive, accessory sex organs, the prostate, seminal vesicles, facial, pubic and axillary hair and sexual performance in males. Testosterone serves as a precursor for estrogens in females, but have no well-defined functions. It is secreted in small quantities by both the adrenals and the ovaries, and 50 60% is derived from peripheral conversion of prohormones, primarily androstenedione. In males, testosterone excess is rarely seen. It is helpful in evaluating hypogonadal states, which result in diminished libido and potency, and in infertility. Common causes of decreased testosterone levels in males in addition hypogonadism are orchidectomy, estrogen therapy, Klinefelters syndrome, hypopituitarism, testicular feminization and hepatic cirrhosis. In females, testosterone deficiency has no known clinical significance. The common cause of increased serum testosterone in females includes polycystic ovaries (Stein Leventhal syndrome), ovarian tumors, adrenal tumors and adrenal hyperplasia. Mild or moderate androgen excess results in menstrual cycle disturbances, and increased facial and body hair. Severe androgen excess usually results in virilization.