A Cortisol test measures the level of cortisol, a steroid hormone produced by the adrenal glands located on top of the kidneys. Cortisol is often called the ‘stress hormone’ as it is released in response to stress and low blood glucose. It plays a critical role in regulating metabolism, reducing inflammation, controlling blood pressure, managing the sleep-wake cycle, and supporting the immune system.
This test is commonly used to diagnose adrenal gland disorders such as Cushing’s syndrome (excess cortisol) or Addison’s disease (insufficient cortisol). It is also used to evaluate adrenal gland function, monitor patients on steroid therapy, and investigate symptoms such as unexplained weight gain, fatigue, high blood pressure, or abnormal blood sugar levels. Cortisol levels naturally vary throughout the day, so the timing of the test is important.
