The DHEA test measures the level of dehydroepiandrosterone in the blood. DHEA is a hormone produced mainly by the adrenal glands and serves as a precursor to male and female sex hormones, such as testosterone and estrogen. This test is used to help evaluate adrenal gland function and to investigate hormone-related conditions, including abnormal hair growth, early puberty, menstrual irregularities, infertility, or signs of adrenal disorders such as adrenal tumors or hyperplasia.