One of the earliest changes is a drop in oxygen levels. As oxygen decreases, people often experience blurred or tunnel vision, ringing in the ears, dizziness, and a fading awareness of their surroundings. Research from the University of Michigan suggests that when oxygen is limited, the brain activates areas linked to memory and visual imagery. This may help explain reports of bright lights or sudden, vivid recollections.
Another surprising finding is that the final moments are not always filled with pain. Studies published in medical journals such as The Lancet indicate that the brain releases large amounts of endorphins and calming neurotransmitters. These chemicals can create a sense of peace or even euphoria, helping reduce stress and fear as the body shuts down.
In recent years, scientists have also observed a brief surge in brain activity just before death. A 2022 study using EEG monitoring found a spike in gamma waves, which are normally associated with heightened awareness, focus, and memory. This suggests that the brain may enter a final state of intense activity before consciousness fades.