There is confusion about the terms of bladder pain syndrome (BPS) and Interstitial Cystitis (IC). The European Society for the Study of IC (ESSIC) classified these according to objective findings . One phenotype, Hunner lesion disease (HLD or ESSIC 3C) differs markedly from other presentations. Therefore, the question was raised as to whether this is a separate condition or BPS subtype. An evaluation was made to explore if HLD differs from other BPS presentations regarding symptomatology, physical examination findings, laboratory tests, endoscopy, histopathology, natural history, epidemiology, prognosis and treatment outcomes. Cystoscopy is the method of choice to identify Hunner lesions, histopathology the method to confirm it. You cannot distinguish between main forms of BPS by means of symptoms, physical examination or laboratory tests. Epidemiologic data are incomplete. HLD seems relatively uncommon, although more frequent in older patients than non-HLD. No indication has been presented of BPS and HLD as a continuum of conditions, one developing into the other. A paradigm shift in the understanding of BPS/IC is urgent. A highly topical issue is to separate HLD and BPS: treatment results and prognoses differ substantially. Since historically, IC was tantamount to Hunner lesions and interstitial inflammation in the bladder wall, still, a valid definition, the term IC should preferably be reserved for HLD patients. BPS is a symptom syndrome without specific objective findings and should be used for other patients fulfilling the ESSIC definitions.