DHEA-S is an androgen derived from DHEA and secreted by the adrenal cortex. It is present in the blood of both men and women, and plays a role in developing male secondary sexual characteristics at puberty. It can also be metabolized by the body into testosterone, androstenedione, or can be changed into the female hormone estrogen. DHEAS secretion is controlled by the pituitary adrenocorticotropic hormone (ACTH) and by other pituitary factors. This test is useful as a marker for adrenal function. DHEAS can be measured to help diagnose adrenocortical tumors, adrenal cancers, adrenal hyperplasia, and to separate these conditions from ovarian tumors and cancers. It is also used to help diagnose polycystic ovarian syndrome (PCOS) and to help rule out other causes of infertility, amenorrhea, and hirsutism. OVERPRODUCTION of DHEAS is seen in adrenal tumors, cancers and hyperplasia. High levels can lead to amenorrhea, and visible symptoms of virilization. In children, excess of DHEAS can cause precocious puberty in boys, ambiguous external genitalia, excess body hair, and abnormal menstrual periods in girls. LOW levels of DHEAS may be due to adrenal dysfunction or hypopituitarism.