A routine blood test is performed by fingertip blood collection and costs$20. A routine blood test can screen the body for many types of illnesses and usually includes white blood cells, red blood cells, and platelets; white blood cells include neutrophils, eosinophils, basophils, and lymphocytes. Changes in white blood cells can occur when the body is infected with bacteria or viruses, for example, when there is a sore throat or purulent tonsillitis, the white blood cells and neutrophils will be significantly elevated. When a person is anemic with fatigue, dizziness, and unsteadiness, hemoglobin and red blood cells will be significantly low. Thrombocytopenia occurs when a person’s blood clotting function is abnormal.