There are many such pain-linked feelings in the repertoire of pain addiction. Understanding the physiological part of emotional pain addiction can make breaking these patterns easier. On a physical level, the addiction is not really to pain, but primarily to free-flowing endorphins that accompany the pain. Endorphins are a hormone-like substance that the body releases whenever a pain or injury is experienced. They are very similar in structure and effect to the opiates, like heroin and morphine.
Endorphins are pain-killers.
When you stub your toe you feel a sharp pain, immediately followed by numbness, which accompanies the anaesthetizing endorphins. The feeling of numbness associated with endorphin release is not unpleasant and, in fact, can be an almost euphoric sensation. People who exercise vigorously are familiar with this feeling. All strain on the body yields endorphins. Emotional stress, like physical stress, leads to strain.