1 Foundations of Health Psychology

Health psychology and its model

Health psychology applies psychological science to understand health behaviors, prevent illness, support recovery, and help people manage health conditions. It examines how biological, psychological, and social influences shape health, illness, and health care.

The biopsychosocial model explains health and illness through interactions among biological processes, a person’s thoughts, emotions, and behaviors, and their social circumstances. It complements biomedical explanations of disease; it does not replace them. No single factor explains every health outcome, and the importance of particular factors varies across people and conditions.

Three interacting domains

Biological factors include genes, age, bodily systems, and existing illness. They may influence vulnerability to disease and how the body responds to stress or treatment.

Psychological factors include beliefs, emotions, expectations, coping skills, and habits. These can affect choices such as whether to exercise, seek care, or follow a treatment plan.

Social factors include relationships, culture, education, income, work, housing, and access to resources and health care. These circumstances can shape exposure to health risks and the options available for responding to them.

How the domains interact

The domains influence one another. Social conditions can shape stress and health habits; psychological responses can affect behavior and bodily processes; and illness can change a person’s mood, relationships, work, and resources. These connections are often reciprocal and can unfold over time.

This interaction means health outcomes should not be reduced to personal choice alone. Circumstances shape the choices available, and no one factor guarantees a particular outcome.

Example: High blood pressure

Consider a person with a family history of high blood pressure. Biologically, inherited risk may make blood pressure more likely to rise. Socially, limited access to affordable healthy food or safe places to exercise may constrain daily choices. Psychologically, ongoing stress or low confidence about making changes may affect coping and health habits.

These influences may reinforce one another. Supportive relationships, accessible care, and practical coping strategies may help, but no single influence determines the outcome. The example illustrates why understanding health may require attention both to individual behavior and to the conditions in which people live.