Accident caused mine, been living with it for more than 20 years
Most of the time, my neck is just stiff, but some times it just makes me want to scream, because it hurts so much and it is a constant pain and no drugs do anything for it.
My lower back is the same - car accident, crushed vertebrae - and when that goes, even co-codamol and the like don't take the edge off of the pain.
Same when I get gout, nothing touches the pain, I just have to put up with it, until the quatazone takes affect.
Apart from mild headaches, I've yet to find a painkiller that actually does anything much.