What is the difference of abnormal psychology to clinical psychology?

Clinical psychology and health psychology are not entirely separated fields of research or practice. Nonetheless, clinical psychology focuses on the causes, prevention, and treatment of abnormal psychological disorders, while health psychology focuses on the causes, prevention and treatment of physical disorders that are impacted by psychological processes. Health psychology grew from clinical psychology as a sub-specialty. It has previously been known as behavioral medicine. How people respond to the dissemination of health education, how they make decisions about harmful behaviors (e.g., smoking or drug use), how they manage complex diseases (e.g., Diabetes), how to impact psycho-physiological disorders (e.g., essential hypertension or psychologically induced urticaria), and how to reduce stress that exacerbates physical disorders are instances of the foci of health psychology. A related field that has emerged over the past couple of decades is psycho-neuro-immunology.