There is the old outdated method of thinking that pain is produced in the part that hurts. We now know that not to be true. Pain is produced 100% of the time in the brain - based on perceived level of threat!
Pain is an alarm system meant to protect you, however sometimes it becomes over sensitive. Have you even known a smoke detector to be over sensitive and go off when you slightly burnt some toast? The house wasn’t on fire but the smoke detector thought it was.
People experience pain differently and in situations people respond to pain depending on context. Imagine this situation: you are a rugby player. Your team and you are practicing. You get caught in a scrum and sustain some superficial injuries. It’s all part of the game, chances are you just deal with it. Imagine you are at the bus stop at night. It’s dark and you’re eating a sandwich. Out of no where this thug appears and attacks you. He snatches your sandwich and throws it on the ground and steals your phone and wallet. In the process of this attack you sustain the same injuries. You are left at the bus stop with these injuries. In these different situations your brain processes pain differently within the context of the scenario.
Another example is: you are crossing the road and you trip and sprain your ankle it is clear that you’ve sprained it badly there is a lot of swelling etc. How much do you think that would hurt (pick a number out of ten, with ten being the worst pain, and zero being no pain at all). Now imagine the same scenario, however as you lay there in the road examining your sprained ankle you look up to see a bus heading straight for you! How much do you think your ankle would hurt in that second scenario? Many people say that they think that the pain would take a back seat to getting out of the way of the bus. This is because temporarily the biggest threat becomes the bus. Therefore it is in your best interest to try to suppress the pain and focus on getting out of the way of the bus.
So in these two examples you learn that pain is not as previously though produced in the part that hurts, but it is a complex system of alarms that is in place to protect you based of perceived threat.
In chronic pain this complex alarm system can become hypersensitive and it keeps going off, giving you a false sense that something is wrong. This is why the structure that is believed to be at fault can be surgically operated on and the patient can still present with pain.