Sensitization is the amplification of danger signalling in any part of the system (which can be driven by both peripheral and central neurology, while centralization is referring only to the latter). It seems like a slam dunk to put these in the “other” category, but not so fast: the nervous system is not being dysfunctional just because it overestimates some danger. Many of us experience normal, healthy centralized sensitization every time we go to the dentist, because our nervous system is not an idiot and is very suspicious of dentists based on past experiences. Our brains think the dentist is a threat, and although they are technically wrong — the dentist is actually there to help — the judgement is not “dysfunctional.”
Sensitization is clearly part of the normal function of the pain system — it’ s not a dumb system where pain is always exactly proportionate to tissue danger. It’s more subtle. Sensitization/centralization is only dysfunctional when it’s chronic and seriously disproportionate. And of course there’s a grey zone a mile wide between normal and dysfunctional. It’s a spectrum.