What happens if a mole grows bigger?

Moles that suddenly appear should be evaluated by a physcian. Sometimes this can happen and they are harmless. What you need to be especially aware of is if the shape of the mole is asymetrical (the two sides are not mirror images of each other), if the border is raised, if the colour varies throughout the lesion, and if the mole itself is bigger then the eraser on the end of a pencil.