Stress is an integral part of life. But what is it, how does it affect the body, and what roles do stress and catecholamines play in acute and chronic manifestations of cardiovascular diseases This book provides a comprehensive, science-based analysis of these issues. Scientific medicine attempts to explain diseases in terms of theories that observation or experimentation can test. The starting point for understanding the roles of stress and catecholamines in cardiovascular disorders is a theory defining stress. This book presents a new homeostatic theory of stress and distress and applies this theory to explain the important roles of endogenous catecholamines--norepinephrine, epinephrine, and dopamine--and other effector systems in maintaining the internal environment during stress. The theory proposes coordinated activation of the body's several stress systems in primitively specific patterns during exposure to various stressors. Comparator "homeostats" interpret afferent information about specific physiological or chemical monitored variables and regulate the operations of effector systems. Via a hierarchical mosaic of central neural cell clusters, the brain constantly redefines homeostasis by resetting homeostats, especially during stress. The presentation summarizes difficult and complex literature about central neural mechanisms participating in sympathoadrenal responses to stress and analyzes theories about the roles of catecholamines in the brain.