A health behavior is defined as an action taken by an individual that influences their health status either positively or negatively. These behaviors include activities like diet, exercise, smoking, and medication adherence, which directly affect health outcomes. Unlike genetic traits, laboratory findings, or disease symptoms, health behaviors are modifiable factors that individuals can control to prevent illness or promote wellness. Understanding and promoting healthy behaviors is a cornerstone of public health and clinical practice aimed at reducing disease risk and improving quality of life.

Reference: Health Behavior: Theory, Research, and Practice, Glanz K., Edition 5.