What Causes Purple Lump On The Anal Region?

Hi there, thank you for tanking the time to respond to me.
I have recently noticed a slightly purple lump at the top of my anus. After some research and looking at other cases on this website I have deducted that it is probably a Hemorrhoid. Is it possible it could be something more serious and how can I treat it. I can give a greater description if needed.
Thanks again, Harley