How do you test for anemia? My doctor told me my RBC count is a bit low. What tests need to be done to identify the various types of anemias?

Hard to. Answer in 400 characters. First question is was your doc talking rbcs count or hemoglobin (hgb) or hematocrit (hct). The evaluation of anemia includes indices of blood production, iron studies, vitamin levels and evidence for blood loss or destruction just to get started.
Anemia. Anemia has many potential causes. Anemia is a result of either the failure to produce enough red blood cells, or the excessive loss or destruction of red blood cells. The type of anemia can generally be diagnosed with simple blood tests. In addition to the cell count, a blood smear can be made to look at the blood cells under the microscope. The shape of the blood cells might give a diagnosis. Iron levels should also be tested for since iron is an essential element in the production of red cells. Other tests might be ordered to check for the destruction of blood cells in the blood stream. Once the type of anemia is diagnosed, further medical test may be necessary since many anemias are a consequence of some other medical condition.