We have built-in analgesic systems
Not only do our brains have systems to process information from nociceptors and register pain, we also have systems that act to suppress the pain experience. Even though mankind has known that the extract of poppies can blunt pain for thousands of years, we did not know how that worked until the 1970s. The reason that morphine and other opiate drugs are effective at reducing and eliminating pain is that they bind to specific receptors on neurons that are important for pain signal processing in the brain, spinal cord, and nerve endings throughout the body. It turns out that these receptors exist because the body and nervous system produce chemicals that act the same way opiate drugs do. This class of “endogenous opioids” includes endorphins, enkephalins, and other related molecules. In a sense, these “endogenous analgesia” systems give our body the ability to control our pain. However, they are not under volitional control in the same way that, for instance, we control our arms and legs. Instead, these systems are engaged by other means. One principle way is by a painful provocation in the first place. That is, whenever a painful event occurs, this system is engaged to suppress the pain signaling, so it would not be as intensive as it would be otherwise. Additionally, acupuncture and cognitive-based pain reduction therapies engage these systems. Even placebo-induced analgesia has been shown to engage some of these systems. There are potentially more ways to exploit these endogenous analgesic systems to benefit those with persistent or recurring pain, and research along these lines continues.
We recommend the following resource for additional information:
The Chronic Pain Research Alliance
