Pain is a very interesting subject to write about. People are often confused by it and the terminology surrounding it, so let's open with some definitions.
Pain threshold is when someone starts to feel pain. Some people will fail to notice an injury that would immediately incapacitate someone else. As a chronic pain sufferer, people assume I have a high pain threshold, but that's not the case. If anything, it's low.
Pain tolerance is how much pain someone can tolerate. This is where I have an extraordinarily high stat; I can ignore a LOT of pain. Mainly because I've had to, since to the best of my recollection I last had a full day without pain... sometime in 1995. More than half my life ago. And even then, days like that were rare exceptions.
