Which hormone is mainly responsible for the body's stress response?

• A. Insulin
• B. Cortisol
• C. Thyroxine (T4)
• D. Adrenaline

Answer: (B)

When the body faces stress, the hypothalamus triggers a cascade that ends with the adrenal cortex releasing cortisol. This hormone helps sustain the stress response by raising blood glucose through gluconeogenesis, mobilizing fatty acids and amino acids for energy, and modulating immune and inflammatory processes. Its effects unfold over minutes to hours and continue after the initial alarm, which is why it’s key for maintaining energy and adaptation during prolonged stress. In contrast, adrenaline acts quickly to prepare for immediate “fight or flight” but doesn’t provide the long-lasting metabolic support. Thyroxine governs overall metabolic rate rather than the specific stress response, and insulin primarily regulates blood sugar after meals rather than coordinating a stress adaptation. So cortisol is the main hormone coordinating the body’s response to stress.