There is more than one school of thought when it comes to PN.
Some call it a disease, others a 'condition' brought about
by something else.
PN can be brought about as a result of another disease or it can be caused by over 200 known causes- some that are diseases, some that are inherited, some that are by (accidental) entrapment of nerves, some that are causing cell death thru chemicals, some that are irritations, & some that are surgical mistakes.
PN can then cause other problems- and ancillary conditions to occur, after it has taken hold.
PN is the cells' mis-firing & sending mixed signals to the brain, that are interpreted as a myriad of symptoms. This can be because of injury, cell death, or various other reasons.
The end result is still, that the cells are sending mixed signals -that we interpret as pain, and symptoms. Or, in the case of cell death- numbness and other types of symptoms.
There has been very little research in many of the various types of PN(with very little success).
Only the most common, such as Diabetic Neuropathy and a very few other causal types.