In microneurography, extracellular neural traffic from single C fibres are recorded. The extracellular action potentials from C fibres are captured, in addition to other traditional measures such as activity dependent slowing and spontaneous activity.  It is not known to what degree action potential shape and amplitude of different C fibres classes differ from each other, and whether action potential morphology changes after nerve injury. Using novel analysis tools, action potential morphology of different C fibres classes, recorded from healthy participants, will be described. Further analysis will describe action potential comparisons between healthy participants, and deeply phenotyped patients with neuropathic pain caused by peripheral neuropathies such as diabetic and small fibre neuropathy. The talk will conclude with how the study of action morphology differences in healthy participants and patients informs physiological physiology function of C fibres in health, and potential pathophysiological mechanisms in neuropathic pain.