Writing characters with Tourette's?

I sort of know how to do the dialogue, but not the ticks, and more importantly, informing the reader. Should I just not mention exactly what it is? I feel weird in the beginning (I write in 1st person) when the character introduces everyone, and it just seems unnatural to me to say something like "here's my friend, who has tourettes."

Same with a stutter, which I'm interested in having a character have that.