Chronic stress is intimately linked to mental health and the development of mental illness, although until recently the reason for the connection was not known. High levels of stress as well as chronic stress are correlated with the development of both anxiety and mood disorders, as well as with relapse in schizophrenia, bipolar disorder and substance use disorders. Chronic stress is also associated with developing physical health problems, such as diabetes, heart disease and cancer. Some stress can be beneficial, preparing you to face a difficult or threatening situation by raising your heart rate or tensing your muscles. The problem is when stress is chronic and the body doesn’t return to its pre-stress physical state.