Stress is your body’s way of responding to any kind of demand or threat. Under stress your body releases chemicals that give you the added strength and energy you need to protect yourself, but it can also shut down your ability to think, feel and act and your body's ability to repair itself. When you feel threatened for any reason – realistic or not—your body's defenses kick into high gear in a rapid, automatic process known as the “fight or flight” response (in rarer, traumatic instances the body may even “freeze”).