Stress is the result of emotional or psychological influences.
Even though physical stress can lead to emotional stress, we will be concerning ourselves here with emotional stress. It is the physiological change that occurs when something happens to you that makes you happy. Like making a good grade on a test or getting the date that you wanted. It is a heightened emotion that occurs when a positive event happens in your life. Another way of looking at it is, it is the physiological change that occurs when something happens to you that makes you unhappy.