About Pain
Pain is the body's natural response to injury and some illnesses. Pain is actually a defense mechanism that signals there is something wrong, meaning you either need to stop doing whatever is causing the pain or seek assistance. The body has special pain receptors, called nociceptors, that send pain signals to the brain. When you receive a pain stimulus, the body releases chemicals that sit on the pain receptors. The pain receptors then convert those chemical signals into electrical signals, which travel to the brain.
About Endorphins
Endorphins are considered the body's natural "feel good" hormones and are similar, in structure, to opiates like morphine. As a matter of fact, the word "endorphin" is actually a mix of two words, endogenous and morphine, which together means morphine from within (the body). We release endorphins during stress and as a response to pain. We also release endorphins during pleasurable activities like sex and exercise--the well-known "runner's high" is a result of endorphins. Endorphins also trigger the reward system, and some people may release endorphins when performing activities like shopping or gambling. The endorphin rush they experience, during these activities, may result in addiction and addictive behavior. It is believed that endorphins also exist to help us override the pain response during fight-or-flight situations.
Endorphins and Pain
Endorphins block pain by sitting on the morphine receptors in the brain. When these receptors activate, they block the pain signals from the nociceptors. The effects of endorphins are only temporary and, if pain persists, endorphin levels will drop. This is because endorphins are only designed to get us through specific pain episodes until we can stop whatever is causing the pain. People with chronic pain may have high levels of endorphins in their blood but no longer respond to the stimulus. There are also those who produce fewer endorphins and have a lower pain threshold.
