Wheel and suspension question

Okay. I'm not sure whether this is true or not however I was told that I would need to do suspension work to my car if I put a bigger wheel on it. The ones that currently sit on my 2000 323ci are 17's and I only want to go up to an 18. Will I have to do anything to the suspension to put that on and everything still run properly.

And just in case fast bob is the one to reply to this because he always seems to find my posts. You da mannnn





~ Zerottie