Nightmares are different for every person. They are as unique as one’s fingerprint, yet the feeling created is universal to all: fear. When you wake from a nightmare, you’re gasping for air, your heart is pounding out of your chest, you’re sweating and shaking all over. Put simply, you are in a physical state of fear, and what you are experiencing is a heightened state of physical arousal (evidenced through the palpitations, the clamminess, and the shaking), better known as the ‘fight or flight’ response.