Cortisol is the major adrenal steroid hormone and is controlled by the pituitary gland and the hypothalamus. The body’s stress increases cortisol in order to mobilize energy to manage and resolve the it. 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 cortisol level. Ideally, this test should be checked in the morning around 8 a.m. Fasting is not required for this test. Take all medications as prescribed.