Its causes are not fully understood but it is thought to be a dysfunction of the central nervous system whose processing of<unk>  signals may have become distorted or sensitised. Specific central nervous system locations that have been suggested are nociceptive neurons, spinal and supraspinal structures, the dorsal horn and others.
Nociplastic pain
Psychogenic pain
Neuropathic pain
Phantom pain
Functional somatic syndrome
Opioid-induced hyperalgesia
Paroxysmal extreme pain disorder
Psychedelic experience