There are two main types of birthmarks: congenital pigmented skin markings
and nevi (moles). Most birthmarks are nothing more then a marking, they
may be unpleasent to the birthmarkee (even having psychological effects if prominent
enough), but they have no medical ramifications. Some birthmarks however, such
as congenital nevi, should be checked out as they have a higher then
normal possibility of becoming cancerous.
Permanent birthmarks may be treated with cryotherapy, surgical removal, or laser surgery. People usally wait until their child is at least school age because birthmarks normally fade. Port wine stains appearing on the face are sometimes treated at a young age with a yellow pulsed dye laser, removing them or at least fading the stain in a futile attempt to avoid the meaness of children.