Haemorrhoids are highly vascular cushions of connective tissue in the anal canal, which are normal structures of the human body. Haemorrhoidal disease in clinical practice means that there is an abnormal enlargement of the anal cushions when these transform into “anal nodules”, bleed and/or prolapse. Haemorrhoidal disease is very common. Despite numerous studies undertaken and knowledge accumulated on the aetiology and pathogenesis of haemorrhoidal disease in the last decade, the specific mechanisms responsible for the development of the disease are not thoroughly understood. The pathophysiology is most likely multifactorial and complex, manifested by muscle weakness, intrarectal prolapse, changes in vascular pressure and flow in blood vessels, malformations, sphincter damage and failure, venostasis, inflammatory reactions, endothelin and collagen abnormalities, matrix metalloproteinases activity, etc. Currently, treatment guidelines for the haemorrhoidal disease are based on Goligher’s classification. The classification of haemorrhoidal disease should be submitted to revision by including aetiological factors, the dynamism of prolapse, symptomatology, enteropathogenesis, and gender characteristics. The present review is focused on recent data gained by exploring the anatomy, pathophysiology, classification, theories explaining the development of haemorrhoids, as well as aetiological invasive and surgical treatment modalities.