Internal hemorrhoids (also called piles) are swollen blood vessels around the inside of the anus in the lower rectum. They are not visible from the outside.

Hemorrhoids are nothing less than vascular dilatations of the venous plexuses that supply the anal region. They may cause bleeding, itching and even exit from the dilated structure through the anal orifice. The larger the hemorrhoid, means that there is a greater extent of dilation, which directly implies treatment. Currently, the classification of the disease varies between grades I and IV, and grades III and IV dilations (prolapse of the structure through the anal canal on exertion, requiring manual maneuver to return to the site or not returning even with assistance) are commonly indicative of surgical treatment.

External hemorrhoids look like swollen, bluish-colored lumps near the opening of your anus. Unlike internal hemorrhoids which are invisible from the outside of your body, you can usually see or feel external hemorrhoids. External hemorrhoids are flat and soft. They are covered with a layer of skin or mucus.

Internal hemorrhoids are graded by the degree of prolapse below the pectinate line into the anal canal. Grade 1: Internal hemorrhoid bulges into the canal but does not prolapse or fall completely into it. These may bleed.