Understanding pain mechanisms
 

I was watching a show on TV, where, in what these days seems to be a common event, someone was getting an organ transplant. For some reason, it got me thinking about pain.

I began wondering whether transplant patients later feel pain the same way in their transplanted organs as in the other organs and body parts that were always 'theirs' so to speak. Do you know how that works?

People with body dismorphic disorder feel like a part that has always been there does not belong to them. But do they feel pain in the limb if they are hurt there? Is it a different feeling, in their minds?

Which also got me thinking, so where do we feel pain exactly? Is pain coming from the organs or muscle tissue or what? What is pain caused by specifically? If someone were to be stabbed, would the pain be in the organ or in something else?

Morbidly, I am also curious what that kind of pain might feel like. If anyone has experienced that kind of 'deep internal tissue' pain, I'd like to hear what you have to say.

Also, why do we feel pain? I know why we feel it, to know there is damage to our bodies, because certain chemicals were released, etc. But why is it unpleasant necessarily?

And from that follows - why do some people have pleasure when they feel pain (e.g. during sex)?

I could have googled the hell out of this but I thought a discussion on the topic on TFP would be far more interesting. Thoughts?

Not quite the same, but I've had serious nerve damage. The best analogy I can come up with is to imagine your nerves are being scraped with a rusty blade that's being lubricated with lemon juice and salt. It's something that I don't think words can really do justice to.

Because if it wasn't, we wouldn't have so much motivation to try and remedy the problem. Imagine a kid touching a hot radiator. As soon as he touches it, he gets his hand as far from it as he can because it hurts. Now, imagine that it's only mildly unpleasant. That same kid may just leave his hand right where it is and do serious damage. It's a motivator to keep us from being too stupid.

Pain causes an endorphine release. It's like a rollercoaster. It'll scare the shit out of you, but you do it anyway because it causes a rush.