This evidence based form of healing involves examining the interactions with the central nervous system, endocrine system, and immune system and how psychological stressors influence these systems. Lifestyle interventions such as breathing, yoga, mediation, mindfulness, humor and guided imagery have been shown to alter the stress response. It is important to understand that the immune system sends signals to the brain which can often lead to altering neural activity which then influences mood, behavior, and health. There is a clear scientific link between stress and illness.