How stress affects your body Your body is hard-wired to respond to stress in ways that don’t fit the types of stress faced by most people today. This reaction, known as the fight-or-flight response, happens naturally without thinking about it. Your body automatically pumps up your heart rate, increases blood flow to the muscles you need, and shuts off blood flow to less vital body functions.
In most cases, once your stress — what your body thinks is a threat — has passed, everything in your body returns to normal. But some people always feel stressed, which means that this fight-or-flight response is always turned on. If your fight-or-flight response is always turned on, over time too much exposure to cortisol and other stress hormones can increase your risk of: | 
