Stress has its place when it is really needed, such as alerting your body to get into action when a calamity is striking. It releases cortisol in stressful situations, which may cloud your mind and thinking, but can help you in survival situations. Neuroscientist Daniel Levitan gives an interesting Ted Talk on ways to help yourself de-stress in stressful situations. His main point is that when you are in very stressful situations, there are things that you can be aware of and prepare for in order to avoid even more stress. Watch here.