Cortisol is a steroid hormone produced in the adrenal glands in response to stress-it’s our primary stress hormone and is responsible for activating the body’s “fight or flight” response in stressful situations. When your body is under chronic stress, your cortisol levels remain high, and you can be more susceptible to disease. Here are six signs that your levels may be elevated. Your cortisol levels should be lower at nighttime, which is what allows your body to relax and recharge.