There are three main types of pain which create different symptoms:
Nociplastic pain can be driven by a mechanism called central sensitisation. Central sensitisation is an increase in sensitivity of various senses and to pain sensations so that the patient feels many more sensations from their body than they normally would. The patient would normally filter out many bodily symptoms as the brain ignores irrelevant sensations, but with central sensitisation this filtering mechanism is diminished. Consequently, they may perceive many more sensations than they used to, some of which are painful. The filtering mechanism is likely to be diminished further when they are stressed, anxious or haven't slept well for a few nights, thereby increasing their symptoms even more.
The focus here is to retrain the brain primarily, not the damaged muscles/ligaments etc.. This is very important to understand.
Helpful short videos links about pain:
Check out this short video which explains central sensitisation more.
What can reduce chronic central sensitisation?