Which hormone is primarily associated with the stress response?

Cortisol is the hormone most closely associated with the body's response to stress. It is produced by the adrenal glands in response to signals from the hypothalamus and pituitary gland as part of the hypothalamic-pituitary-adrenal (HPA) axis. During stressful situations, cortisol helps mobilize energy by increasing blood glucose levels, suppressing non-essential functions, and modulating the immune response.

The primary role of cortisol in the stress response includes facilitating the body's ability to manage prolonged stressors, promoting resilience, and improving overall physical capabilities to handle challenging situations. It affects various processes in the body, including metabolism, inflammation control, and the maintenance of homeostasis.

In contrast, although adrenaline is also a stress-related hormone, it acts rapidly in acute stress situations by producing immediate effects such as increased heart rate and blood flow to muscles. Insulin, on the other hand, is involved in glucose metabolism and does not play a direct role in the stress response. Serotonin is a neurotransmitter that influences mood, but it is not the primary hormone responsible for managing stress responses.