This paper presents the current knowledge about the neuroendocrine physiological mechanisms which are activated within the body when encountering stress, i.e. disturbances in homeostasis, and the ways in which the body tries to return to the previous state after the stress response cascade has been initiated. Primarily the hypothalamic-pituitary-adrenal axis (HPA axis) and the sympathetic nervous system (SNS) are described, but also other individual neural, neuroendocrine and endocrine axes and their features. The paper provides an overview of the aspects that make up the response to stress in different classes of vertebrates, specifically fish, amphibians, reptiles, birds and mammals. A significant part of the thesis is devoted to the description of the physiological and metabolic changes that occur when a person is faced with a negative psychosocial stimulus and the potential health consequences of chronic stress. At the end, the findings of recent scientific research on the concept of stress resilience, the consequences of low or high resilience, and the potential actions that a person can take are elaborated.