Psychology

Psychology is the scientific study of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, including feelings and thoughts. It is an academic discipline of immense scope, crossing the boundaries between the natural and social sciences. It looks at the ways people think, act, react, and interact. It is the study of human (and animal) behaviour, and the thoughts and emotions that  guide ourbehaviour.
Psychologists seek an understanding of the emergent properties of brains, linking the discipline to neuroscience.

Behavioral science describes the study of human behavior through the use of systematic experimentation and observation. In particular, behavioral science studies the way that emotions, the environment and social factors influence our decisions.

Health psychology is the study of psychological and behavioral processes in health, illness, and healthcare. It is concerned with understanding how psychological, behavioral, and cultural factors contribute to physical health and illness. In terms of health psychology, we understand health to be the product not only of biological processes (e.g., a virus, tumor, etc.) but also of psychological (e.g., thoughts and beliefs), behavioral (e.g., habits), and social processes which is linked with biopsychosocial model. We can understand better all the factors that allow people to be healthy, recover from an illness or cope with a chronic condition.