A cortisol test is done to measure the level of the hormone cortisol in a 24-hour sample of urine. The cortisol level may show problems with the adrenal glands or the pituitary gland. Cortisol is made by the adrenal glands .
Cortisol is a steroid hormone and helps regulate metabolism, reduce inflammation and control blood sugar levels and is produced by the adrenal glands. It rises in response to stress, but it will also rise in those taking steroids (even as creams or asthma inhalers) and briefly after eating. Persistently raised cortisol levels may indicate underlying Cushing's disease. Too little cortisol may indicate adrenal deficiency and Addison’s disease. Cortisol levels naturally deplete throughout the day so a 9am sample is best.