When your doctor orders a CBC, there are no special preparations you'll need to take before the test. You are not required to fast (not eat solid foods for 12 hours or so), unless you are having other tests done at the same time that require it.
Does fasting affect CBC results?
Conclusions: Food consumption impacts CBC results. To ensure the consistency, quality, and repeatability of CBC analysis, blood should be drawn from fasting patients.
What blood tests require fasting?
Blood tests that you will likely need to fast for include:
- blood glucose test.
- liver function test.
- cholesterol test.
- triglyceride level test.
- high-density lipoprotein (HDL) level test.
- low-density lipoprotein (LDL) level test.
- basic metabolic panel.
- renal function panel.