The Testosterone test measures the level of testosterone, a key hormone responsible for sexual development, muscle mass, and bone density, in the blood. It is commonly used to evaluate hormonal imbalances, assess fertility, and diagnose conditions like hypogonadism in men and polycystic ovary syndrome (PCOS) in women. Abnormal testosterone levels can also indicate adrenal or pituitary gland issues. This test may be part of a broader hormone panel for a comprehensive assessment.