What approach should a new PA use to interpret borderline CBCs in primary care?

[TimothyXW]

As a new physician assistant in a primary care clinic, I'm gaining confidence with most lab work, but I still find myself second-guessing my interpretation of borderline Complete Blood Count results, especially when it comes to subtle shifts in lymphocyte differentials or mild macrocytosis that don't clearly point to a single diagnosis. I worry about missing something significant versus ordering unnecessary follow-up tests that alarm patients. For more experienced clinicians, what's your systematic approach to interpreting a CBC beyond just the highlighted abnormal values? How do you contextualize minor abnormalities with a patient's history and other labs, and what are the key red flags in a CBC that you feel always warrant a hematology referral versus continued monitoring in primary care?