Hello
Piles are varicosities or swelling and inflammation of veins in the rectum and anus.
Check this link
http://en.wikipedia.org/wiki/Hemorrhoid
Possible complications of piles
strangulation - when a pile that sticks out of the body (prolapsed pile) swells considerably and the blood flowing into it cannot return to the body.
thrombosis - if the blood in the swollen pile clots, forming a thrombosed pile.
gangrene (tissue death) - if there is a lack of blood supply to a pile.
infection - where an abscess may form around the rectum and anus causing pain and swelling