Stress is simply a reaction to a stimulus that disturbs our physical or mental equilibrium. In other words, it’s an omnipresent part of life. A stressful event can trigger the “fight-or-flight” response, causing hormones such as adrenalin and cortisol to surge through the body A little bit of stress is exciting—it keeps us active and alert. But chronic stress can have detrimental effects on health. You may not be able to control the stressors in your world, but you can alter your reaction to them.