As someone with chronic pain, nope, I don't think one builds up a tolerance to it. Instead, I think I'm lucky in that the severity waxes and wanes. Below some threshold it recedes from being pervasive, going into the background and I have to go consciously looking for it to see if I'm still feeling it.

Exceed that threshold and it's always there, front and centre, just pain. At that point, as throwaway91214 says, I consciously try to ignore it.

When it exceed the next threshold, life pretty much stops for awhile until it recedes again. Those are the sleepless nights and long, minimal days.

(I use the notion of thresholds for simplicity, it's perhaps closer to an exponential scale).

I've had mine for about eleven years. Such is life.