Over the past 30 years there has been over 300 studies have been done on stress and immunity in humans. They have showed that psychological challenges are capable of modifying various aspects of the immune systems. Most studies on stress have defined it as " circumstances that most people would find stressful". These are defined as stressors. But the big question that must be answered is, How does stress get into the body to impact the immune system?
This requires a lengthy discussion explaining how the immune system, endocrine system and hormonal system function both independently of one another and dependent upon one another in order to maintain internal "homeostasis". Simply put, there are fibers that connect the brain, the nervous system and the endocrine system, referred to as the hypothalamic-pituitary-adrenal axis all secrete hromones that control many bodily functions. This is a relationship that needs when functioning normally leads to normal physiological and psychological function. Stress, whether acute or chronic leads to adaptations that over days, months and even years may lead to altered metabolic functioned.
Next: Who is vulnerable to stress-induced immune changes.