Health psychology is a subfield of psychology that focuses on understanding how psychological, behavioral, and cultural factors contribute to physical health and illness. Here are some key concepts, theories, and contributors in health psychology:

1. Biopsychosocial Model
   • Theorists/Contributors: George Engel
   • Description: The biopsychosocial model considers biological, psychological, and social factors and their complex interactions in understanding health, illness, and healthcare delivery.
2. Health Belief Model
   • Theorists/Contributors: Irwin M. Rosenstock, Godfrey Hochbaum, S. Stephen Kegeles, Howard Leventhal
   • Description: This theory explains health behaviors by focusing on the attitudes and beliefs of individuals. It is used to predict how people will behave when it comes to maintaining health and when they might take action to treat an illness.
3. Theory of Planned Behavior
   • Theorists/Contributors: Icek Ajzen
   • Description: This theory states that attitudes, social norms, and perceived behavioral control influence intentions, which in turn, predict behavior. It is widely used to understand and predict health behaviors.
4. Transactional Model of Stress and Coping
   • Theorists/Contributors: Richard S. Lazarus and Susan Folkman
   • Description: This model explains the complex processes through which people react to and cope with stress. It emphasizes the cognitive appraisal of stress and available coping resources.
5. Self-Efficacy Theory
   • Theorists/Contributors: Albert Bandura
   • Description: This theory explains how people’s beliefs in their ability to perform specific tasks can influence their health behaviors. High self-efficacy is associated with a greater likelihood of adopting healthy behaviors.
6. Stages of Change Model (Transtheoretical Model)
   • Theorists/Contributors: James O. Prochaska, Carlo C. DiClemente
   • Description: This model describes how people modify a problem behavior or acquire a positive behavior. It includes stages such as pre-contemplation, contemplation, preparation, action, maintenance, and termination.
7. Self-Determination Theory
   • Theorists/Contributors: Edward L. Deci and Richard M. Ryan
   • Description: This theory focuses on the motivation behind choices people make regarding their health, without external influence, and emphasizes the role of autonomy, competence, and relatedness.
8. Social Support and Health
   • Theorists/Contributors: Various
   • Description: Research in this area examines how social relationships influence health and well-being. Social support can buffer against stress and is associated with better physical and mental health outcomes.
9. Psychoneuroimmunology
   • Theorists/Contributors: Various
   • Description: This interdisciplinary field examines the interaction between psychological processes, the nervous system, and the immune system, and how these interactions affect health.
10. Pain Management and Control
    • Theorists/Contributors: Ronald Melzack, Patrick D. Wall
    • Description: This area focuses on the psychological techniques used in the management and control of pain, including the Gate Control Theory of Pain.
11. Health Promotion and Disease Prevention
    • Theorists/Contributors: Various
    • Description: This involves applying psychological principles to promote health behavior and prevent illness. It includes education, behavior change interventions, and health policy.

These areas and theories form the basis of health psychology, helping to understand and promote health behaviors, and to prevent and treat illnesses through the integration of psychological knowledge and principles.