Doctors may prescribe a complete blood count test as a part of their routine full body check-up or when they need a detailed evaluation of the overall health of the person. The test helps to detect and monitor disorders, infections, immune system problems, blood cancers, and so on. A complete blood count is a standard blood test that is usually prescribed by doctors as part of a routine examination. The price of a CBC test may vary from one lab to another. However, the difference is not much significant.