Hidradenitis suppurativa (HS) is a chronic, recurrent, often debilitating inflammatory disease of the pilosebaceous follicle, typically appearing after puberty with deep, painful, inflammatory nodules and abscesses in the intertriginous areas. Contrary to acne, it occurs most commonly in the axillary, inguinal, anogenital and inframammary regions, and is sometimes referred to as acne inversa. The prevalence of HS in Europe has been estimated to be approximately 1%, with women being affected about three times more often than men. The condition has its peak incidence in the second and third decades of life. The disease has been associated with multiple comorbidities, including follicular occlusion syndromes, inflammatory bowel disease, metabolic syndrome, arthritis and depression. Hidradenitis may also appear in association with autoinflammatory syndromes, like the PASH, PAPASH, PsAPASH and PASS syndroms. The disease is caused primarily by follicular occlusion, with secondary involvement of the apocrine glands. The etiology is still not fully elucidated; however, it involves disrupted innate immune response and disease-associated risk factors such as smoking, obesity and genetic mutations. Clinically, characteristic skin lesions are subcutaneous nodules, deep dermal abcesses, double comedones and sinus tracts. As the disease process continues, fibrosis, induration of the skin and dermal contractures occur. Diagnosis is made clinically, based on the characteristic skin lesions. The Hurley staging system of HS helps faciliate therapeutic decision. According to the European guidelines, locally recurrent lesions can be treated with classical surgery (excision) or laser techniques. However, widely spread lesions require drug treatment, either as monotherapy or in combination with radical surgery. Drug therapies include topical or systemic antibiotics (tetracyclines or clindamycin and rifampicin), retinoids (acitretin) and biologics (adalimumab and infliksimab). In order to prevent the devastating consequences of the disease and improve the quality of life in patients, early diagnosis and treatment of HS are extremely important.