Nociceptive

Musculoskeletal

Bone, joint, muscle trauma, or inflammation
Mechanical instability
Muscle spasm
Secondary overuse syndromes

Visceral

Renal calculus, bowel, sphincter dysfunction, etc.
Dysreflexic headache

Neuropathic

Above Level

Compressive mononeuropathies
Complex regional pain syndromes

At Level

Nerve root compression (including cauda equine)
Syringomyelia
Spinal cord trauma/ischemia (transitional zone, etc.)
Dual-level cord and root trauma (double lesion syndrome)

Below Level

Spinal cord trauma/ischemia (central dysesthesia syndrome, etc.)