No Yorkies are not a sickly breed - they or some of them anyway may be tiny and they can be a bit of a challenge due to tiny stomachs that can't hold much food at one time and needing to eat often to keep from going into low blood sugar ( hypoglycemia) but in general they are sturdy little guys and gals.
Yes you hear on here about ones that do have a problem and that is because the wonderful owners on here know that someone may have a answer to their problem - just look at how many members there are here and what the small precentage of real health issues there are - I know from experience that all breeds have some issues and good breeders don't perpetuate that problem by breeding dogs with those issues .
I hope you don't shy away from a wonderful breed like a Yorkie because of what might happen - you could have the same thing with any breed , a real child or anyone in your life . Just jump in , get a baby and ENJOY
