Human Body
Why Do We Feel Pain? The Science of Nociception
Pain is not a sensation but a perception — the brain's interpretation of a threat signal from specialized nerve endings called nociceptors. When you touch a hot stove, nociceptors detect the temperature change and fire electrical signals up the spinal cord to the brain. The brain then constructs the feeling of pain, which is why you can feel pain from a phantom limb that no longer exists, or feel no pain during surgery under anesthesia despite injury. Pain serves a critical protective function, preventing injury, but when it persists beyond healing (chronic pain), it becomes a malfunction of the nervous system.