Why do i have a large purple lump on the right side of my tongue?

See a Dentist: A large purple lump on the side of the tongue is a serious concern. Without a visual exam and knowing more, it is impossible to tell you what it is. It could be cancer. It could be a blister. And there are several other possibilities. Please see a dentist asap to have it evaluated.

Get it checked: There are several things that may cause this and it is not possible to give you a good answer. You need to see you dentist for an evaluation.