Stress is a state of homeostasis that is usually stimulated by an adverse force that is being established due to a physiological response. This chapter explains in detail the stress response system that are being regulated by the adrenal gland hormones when stimulated. Most of the hormonal changes are increased due to stress which includes growth hormone, prolactin, and glucocorticosteroids. An Increase in stress levels may lead to different changes in the body of humans or other animals which may lead to an imbalance in body features. Stress systems are being discussed in this section even though it is not separate organ because they play a vital role in regulating different body systems.