An **Androstenedione (A4) Diagnostic Test** measures the levels of androstenedione, a steroid hormone and precursor to testosterone and estrogen, in the blood. This evaluation is primarily ordered by physicians to investigate signs of hyperandrogenism, such as excessive hair growth (hirsutism), severe acne, irregular menstruation, or premature puberty.

By evaluating A4 levels, healthcare providers can assess the function of the adrenal glands and ovaries. It serves as a vital tool in diagnosing and managing conditions like Polycystic Ovary Syndrome (PCOS), Congenital Adrenal Hyperplasia (CAH), and androgen-secreting tumors, guiding targeted clinical interventions.