Reticulocytes are immature red blood cells and are measured to evaluate the function of bone marrow. Normally as it matures, the red blood cell loses its nucleus. The remaining parts of the cell produce a characteristic color making them easy to identify. Reticulocytes are increased in conditions such as chronic blood loss, hemolytic anemia, iron deficiency anemia and thalassemia. Reticulocytes will decrease in alcoholism, anemia of chronic disease, kidney dysfunction, and endocrine disease. Fasting is not required for this test. Take all medications as prescribed.