There are two broad classifications of hemorrhoids based on their location within or outside the anus.

Internal Hemroids
Internal hemorrhoids develop on the inside walls of the anus, and they are not easy to see or even feel from outside except with the aid of some instruments the doctors use.

When hemorrhoid enlarge they may start bulging or hanging out of the anus, especially when the patient is passing stool. This will make them look as if they are on the outside of the anus, whereas they actually have their roots inside and are therefore still internal hemroids.

External Hemroids
External hemorrhoids on the other hand mainly attack the outside parts of the anus, especially around the opening where they can be seen as small lumps. Their location means that they can easily be reached by the hand and can therefore be scratched or rubbed. However, this can bring in other complications such as infection and ulceration. External hemorrhoid should be treated immediately to avoid other infections.