COR | Cortisol

Cortisol (COR) is the main glucocorticoid produced in the adrenal cortex. Cortisol concentration is most frequently tested in diagnosing diseases caused by excessive cortisol production in Cushing's syndrome, adrenal steroid deficiency in Addison's disease, and for monitoring treatment. Increased serum concentration is observed during stress response, psychiatric disorders, obesity, diabetes, alcoholism, and pregnancy, which can cause diagnostic challenges in Cushing's syndrome. Low cortisol concentration is found in patients with rare adrenal enzyme deficiencies and those experiencing prolonged stress. Normally, the highest cortisol secretion is detected in the second half of the night, and the peak cortisol concentration is reached early in the morning. Subsequently, cortisol concentration begins to drop throughout the day, with the lowest concentration reached in the first half of the night. Therefore, when taking cortisol samples, it is necessary to consider the circadian variations in cortisol secretion and the impact of stress.