Abstract
Psychological and social factors are thought to influence risk for a range of physical illnesses including coronary heart disease, high blood pressure, type 2 diabetes, infectious illness, bronchial asthma and musculoskeletal pain. These associations are underpinned by the impact of psychological stress and other biobehavioral stimuli on the systemic biological responses implicated in disease risk. Several systems are involved, with cardiovascular, neuroendocrine, immune, inflammatory, metabolic and musculoskeletal responses all being relevant. The nature and extent of influence on health outcomes varies across diseases, and different types of study design are needed to evaluate these processes in different health conditions.