R.J.
answers from
Seattle
on
Totally depends. A CBC is a fast test (because you just have to look under a microscope... not grow anything), so in the ER, not long. If you're getting a cbc done at a doctor's office it depends on whether they have a lab there or they send it out to a lab. If they're sending it out to a lab, typically, it takes about a week to 10 days.