There is provided an apparatus for determining a pain threshold of a subject, the apparatus comprising a processing unit adapted to monitor the subject to identify a suitable time for determining the pain threshold of the subject control a first electrode to deliver an electric signal to a sural nerve of the subject at an identified suitable time receive a first output signal from a first sensor that measures a reaction of a muscle of the subject to the electric signal and determine the pain threshold of the subject from the received first output signal.
