Can you clarify what chronic pain really is?

Brain Disease. A chronic pain syndrome implies that the pain has caused a "rewiring" of the circuits in the brain.This condition is in addition to whatever set up this condition in the brain in the first place.Treatment now needs to be directed to the brain disease as well as the inciting cause. The amount of time needed to start this condition is variable from days to months.
Difficult. Chronic pain implies more than that the pain has lasted a long time. As opposed to acute pain where there is a significant element of inflammation, chronic pain has abnormalities in the pain processing parts of the central nervous system. This is why we consider different types pf medications.