Piles/ Hemorrhoids are collections of inflamed tissue in the anal canal. They contain blood vessels, support tissue, muscle, and elastic fibers. Nearly three out of four adults will have hemorrhoids from time to time. Hemorrhoids have a number of causes, but often the cause is unknown. They can have a range of sizes, and they may be internal or external. Internal piles are normally located between 2 and 4 centimeters (cm) above the opening of the anus, and they are the more common type. External piles occur on the outside edge of the anus.