In addition to the HIV test, there are many HIV lab tests your doctor will order on a regular basis. One of the most important is a complete blood count (CBC). While there are many different types of cells in your blood, they can all be grouped into one of three categories: red blood cells, white blood cells, or platelets. From a complete blood count, your doctor can determine if you have an infection and how well your body is making blood cells. Let's look at the types of cells measure as part of a complete blood count.