The present invention addresses the problem of providing a system and a method for noninvasively and conveniently diagnosing difficult-to-diagnose chronic pain-related diseases and/or diseases requiring differentiation from the chronic pain-related diseases. The problem was solved by providing a method for obtaining an indicator for determining the presence and/or type of a chronic pain-related disease and/or disease requiring differentiation from chronic pain-related diseases, the method comprising: (a) performing an offset measurement test of pain on a subject that does not suffer from a neurological disorder; (b) analyzing the results obtained from the test in (a); and (c) comparing the analysis results obtained in (b) with a reference value.