Cortisol is the major adrenal steroid hormone and is controlled by the pituitary gland and the hypothalamus. The body’s stress response increases cortisol in order to mobilize energy to manage and resolve the stressor.

Chronic stress can fatigue the adrenal gland which can disrupt its normal diurnal control over cortisol. This disruption can lead to symptoms like fatigue, weight gain, insomnia, depression, and anxiety.

So if you’re feeling tired and stressed out, check your cortisol level.

Typically cortisol is highest in the morning and drops during the day for most people. Some people have a “reverse” cortisol curve where it is higher at night instead of being highest in the morning. Obtaining a morning and late afternoon cortisol value provides more information regarding an individual’s daily fluctuation in cortisol. Also, in conjunction with DHEA-S, a cortisol test allows your doctor the opportunity to better evaluate overall adrenal function.

Instructions

Since cortisol levels normally fluctuate throughout the day, a blood level is checked in the morning around 8 a.m. and again in the afternoon around 4 p.m. Fasting is not required for this test. Take all medications as prescribed.