Adrenaline is the key to your fight-or-flight response. Produced in the adrenal glands, the hormone floods the blood during high-stress situations and sends a message to other areas of the body to be on alert. While adrenaline is an evolutionary response that has been critical to our survival, prolonged spikes in the hormone caused by things like chronic stress can have an adverse effect on health, including causing problems with insomnia, anxiety, heart disease, and more. Excess adrenaline can also produce extra cortisol and together can lead to acne, dullness, and wrinkles.