Cortisol is primarily known as a hormone involved in:

Cortisol is primarily recognized for its crucial role in the body's stress response. When an individual experiences stress, whether physical or emotional, the body activates the hypothalamic-pituitary-adrenal (HPA) axis, leading to the release of cortisol from the adrenal glands. This hormone helps mobilize energy by increasing glucose availability in the bloodstream, enhancing brain function, and modulating other hormone levels to prepare the body for a "fight or flight" response.

Cortisol also plays a fundamental role in regulating various bodily functions, including metabolism and immune response modulation. While it does have effects on other aspects, such as regulating sleep patterns and influencing bone density, its most significant and immediate impact is during periods of stress, which is why it is primarily associated with the stress response.