Internal piles are often graded, a rating system that ranges from first degree to fourth degree, with the most severe examples being a fourth degree pile.
First degree piles are swollen vessels in the rectum, also known as "internal" haemorrhoids.
Second degree internal piles are larger, and protrude through the anus when having a bowel movement, but return to their position inside the rectum.
Third degree internal piles protrude from the rectum and must be pushed back up into the rectum as they will not return on their own.
Fourth degree piles cannot be pushed into the rectum and permanently descend through the anus.
Second through fourth degree piles are referred to as "prolapsed" when they are protruding out of the body.
External piles, which originate outside of the rectum/anus, are not graded.