Why do you wake up from a dream when you die?

As a subject matter expert in the field of sleep and dream studies, I can provide some insights into the phenomenon of waking up from a dream when you seemingly die within it. When you experience a dream in which you die, it can be a very intense and emotional event. This is because such dreams often involve a fight-or-flight response, which is a physiological reaction that occurs in the presence of a perceived harmful event, or threat to survival. The body's response to this perceived threat is to prepare for action by increasing the heart rate, blood pressure, and adrenaline levels. Adrenaline is a hormone that is released by the adrenal glands in response to stress or danger. It increases alertness, concentration, and the body's overall readiness to respond to the situation. When you dream about dying, your brain may simulate this response, causing the release of adrenaline. Since the body cannot be in a state of deep sleep and have an adrenaline rush at the same time, the increased heart rate and alertness can trigger you to wake up. Moreover, dreams where you die and subsequently wake up are often more memorable. This is because the act of waking up interrupts the usual dream process, making the dream more likely to be recalled. In contrast, most dreams are not remembered because they occur during the rapid eye movement (REM) sleep stage, and the brain does not have the same level of alertness to record and retain the information as it does when you wake up.

Dying in a dream is a stressful event, which causes your brain to release adrenaline. You can't sleep and have an adrenaline rush at the same time so you wake up. These dreams where you die and wake up are usually more memorable due to the fact that you wake up whereas most people don't remember 95% of their dreams.