Physical disorders can affect psychological states.
Pain associated with physical disorders may cause sleep disturbances and alter one's usual routines and ways of coping, producing distortions in thinking and appraisal of problems. It can also reduce one's confidence in managing problems. Each of these factors can result in depression or anxiety. Psychological states such as depression and anxiety can alter immune function and other biological processes, which leads to poor health practice and diminished use of the health care system. Any of these factors can create a physical disorder.