Hemorrhoids (Piles) By Parswa Ansari, MD, Hofstra Northwell-Lenox Hill Hospital, New York Reviewed / Revised Jan 2023 View Patient Education Symptoms and Signs Diagnosis Treatment Key Points More Information Topic Resources Hemorrhoids (External) Classification of Internal... How To Do Hemorrhoidal Thrombecto... Hemorrhoids are dilated vessels of the hemorrhoidal plexus in the anal canal.