Which hormone is primarily produced by the adrenal glands when the body is under stress?

The hormone primarily produced by the adrenal glands when the body is under stress is cortisol. Cortisol is a steroid hormone that plays a critical role in the body’s stress response. When faced with a stressor, the hypothalamus signals the adrenal glands to release cortisol into the bloodstream. This hormone helps mobilize energy by increasing blood sugar levels, enhances the body’s ability to utilize fats and proteins, and aids in various physiological functions to prepare the body for a "fight or flight" response.

Cortisol also has anti-inflammatory effects, which can help modulate the immune response during times of stress. The production of cortisol is part of the hypothalamic-pituitary-adrenal (HPA) axis, which is activated in stressful situations.

While adrenaline, also known as epinephrine, is produced by the adrenal medulla and also plays a significant role in the body’s fight-or-flight response, cortisol is the primary hormone associated with prolonged stress responses and metabolic adjustments. Other hormones like insulin and thyroxine are involved in metabolism and energy regulation but are not specifically tied to the acute stress response in the context of the adrenal glands.