An excerpt from my transcutaneous electrical stimulation (TENS) article, describing an important basic principle that explains why so many people “swear by” so many different kinds of treatment methods:
Pain is completely controlled by an overprotective brain that likes to sound the alarm too loudly, too often, regardless of what’s actually going on in tissues. This means that most kinds of chronic pain are partially and briefly treatable with tricks and hacks. Almost any reassuring and/or distracting input has some potential to persuade the brain to dial pain down a bit, by fooling a brain into thinking there’s no cause for alarm, at least for a little while. Brief, modest treatment results for chronic pain are mostly about how pain works… not how the treatment works.
Unfortunately, your brain is stubborn and it’s hard to convince it to shut up about pain completely, short of knocking it out, which is why anaesthesia is the only truly effective analgesia.