Adult men have the diagnosis of anemia if their hemoglobin level is below 13.5g/dL, and women are anemic if their level is below 12g/dL, according to Charles Linker, M.D., clinical professor of medicine at the University of California, in "Current Medical Diagnosis & Treatment." The different diagnostics for anemia all work together to determine the type of anemia and the cause.
Complete Blood Count
The complete blood count, or CBC, gives information about white blood cells, platelets and red blood cells. It provides the total number of red blood cells, the amount of hemoglobin, the hematocrit, the mean corpuscular volume, the mean corpuscular hemoglobin concentration and the mean corpuscular hemoglobin. Hemoglobin is the protein in the red blood cell where the oxygen molecule attaches. The hematocrit tells how much of the blood volume is made of red blood cells. The mean corpuscular volume, or MCV, is the average volume of red blood cells. Physicians use it to determine the average size of the cells. People with an MCV below 80fL have a microcytic anemia, or an anemia in which the red blood cells are smaller than normal. Those with a MCV above 100fL have a macrocytic anemia, with red blood cells larger than normal. Dr. Linker writes in “Current Medical Diagnosis & Treatment” that iron deficiency anemia is a microcytic anemia. Vitamin B12 deficiency is a macrocytic anemia. Physicians use the mean corpuscular hemoglobin concentration and the mean corpuscular hemoglobin to determine the average amount of hemoglobin.
Blood Smear
In a blood smear, the lab looks at a sample of blood under a microscope. In the Merck Manual for Healthcare Professionals, Alan Lichtin, M.D., of Hematologic Oncology and Blood Disorders at the Cleveland Clinic writes about the abnormal red blood cells the lab may find. The lab looks for any parasites in the red blood cells, injured cells, changes to the membrane and any abnormal shapes or sizes. The abnormal cells help diagnose the cause of the anemia.
Reticulocyte Count
Blood cells are made in the bone marrow. Reticulocytes are young red blood cells that leave the bone marrow and enter the bloodstream. People with anemia who have a high number of reticulocytes are having their red blood cells destroyed. The bone marrow works and is making many new red blood cells. A low number of reticulocytes in anemics means the bone marrow isn't making the normal amount of red blood cells. There is a problem within the bone marrow. The lab can see the reticulocytes when it mixes a blood sample with a dye called methylene blue. Structures inside the reticulocytes, called ribosomes, become dark blue, as explained by Marshall Lichtman, M.D., professor of medicine at the University of Rochester Medical Center, in “Lichtman's Atlas of Hematology.”
Bone Marrow Biopsy
A bone marrow biopsy is not a routine diagnostic, writes Dr. Lichtin in the Merck Manual for Healthcare Professionals. Reasons for an anemic person to have a bone marrow biopsy include the possibility of multiple myeloma or leukemia, lab results of a low number of blood cells, or results of high numbers of white blood cells or platelets. Multiple myeloma and leukemia are cancers involving the white blood cells.
References
- “Current Medical Diagnosis & Treatment 2010”; Stephen McPhee, M.D., Maxine Papadakis, M.D.; 2010
- “Lichtman's Atlas of Hematology”; Marshall Lichtman, M.D., Jean Shafer et al.; 2007
- The Merck Manual for Healthcare Professionals: Evaluation of Anemia
