<b><i>Background:</i></b> Hidradenitis suppurativa/acne inversa (HS) is a chronic, inflammatory, recurrent, debilitating disease, which inflicts a significant burden on patients and is associated with comorbid disorders, such as significantly reduced quality of life, depression, stigmatization, inactivity, working disability, impairment of sexual health and several cardiovascular risk factors. <b><i>Aims/Methods:</i></b> To implement an expert consensus on the diagnostic criteria, severity and classification assessment, and an assessment of anti-inflammatory treatment effectiveness based on current evidence. <b><i>Results:</i></b> This article provides criteria for diagnosis, severity assessment, classification and evaluation of HS patients. <b><i>Conclusion:</i></b> The provided criteria can be used as tools for the promotion of uniformity in HS evaluation and facilitation of early and timely identification and referral in the primary care setting and thorough and efficient evaluation in daily clinical practice.