Is fasting required for a complete blood count (CBC)?

A complete blood count (CBC) does not require fasting, as it is unaffected by food intake. Therefore, a CBC can be performed regardless of the patient’s physical condition. A standard CBC typically includes three major components: red blood cell count and hemoglobin measurement, white blood cell differential and total count, and platelet count. In most cases, a CBC is not necessary for common colds; however, if fever is present, a CBC may be performed to help clarify the underlying cause.