Failure to pass a routine blood test indicates that there are abnormalities in the ratio, number or other problems of various blood cells in the blood. There can be an abnormal number of white blood cells, either an increased number of white blood cells or a decreased number of white blood cells, or an abnormal ratio of various cells in the white blood cells, or an increased or decreased number of neutrophils, an increased or decreased ratio of lymphocytes, as well as an increased or decreased number of eosinophils, an increased or decreased number of basophils, or an increased or decreased number of monocytes. Each type of cell count increase or decrease represents a different clinical significance. Changes in red blood cells may also be present, such as increased red blood cell count and decreased red blood cell count, and decreased red blood cell count can present as anemia. There may also be changes in the mean volume of red blood cells, the mean hemoglobin volume, and the mean hemoglobin concentration, and there may be increases and decreases in the number of platelets.