Anemia is a medical condition characterized by low levels of hemoglobin in the blood. This produces symptoms such as fatigue, weakness and dizziness. Several anemia blood tests are used to reach a diagnosis. Iron deficiency and certain vitamin deficiencies usually lead to low hemoglobin levels.
What are the Signs of Anemia?
Tiredness, weakness, dizziness, irritability, shortness of breath and depression are the common signs of anemia. Additional symptoms include cold hands and feet, pale skin and chest pain. Some individuals have unusual cravings for ice and have difficulty focusing or concentrating.1
Complete Blood Count Test
If your symptoms point toward anemia, the doctor will order several anemia blood tests. A complete blood count test determines the level of hemoglobin and red blood cells in the blood. Hemoglobin is responsible for transporting oxygen to cells. If the hemoglobin level is less than 13.0 g/dL for men and less than 12.0 g/dL for women, anemia is the diagnosis.1 Symptoms usually appear when the hemoglobin level drops below 9.5 g/dL. The percentage of red blood cells in the blood, called the hematocrit, can also be used to determine if anemia is present. A hematocrit level less than 39% in men and less than 36% in women indicate anemia.1
Iron Deficiency Tests
Once a diagnosis of anemia is made, the cause for it is identified. The doctor will order a ferritin blood test to measure the level of ferritin, a protein found in cells that store iron. Serum ferritin levels directly relate to the amount of iron in the body. The normal range for males is 12-300 ng/ml and the normal range for females is 12-150 ng/ml.2 A low ferritin level indicates a low iron level. Iron deficiency is the most common cause of anemia.
A second test called total iron-binding capacity determines how much iron is transported in the blood by the protein transferrin. The test measures the amount of transferrin that isn't bound to iron. If this level is high, it means that a small amount of iron is being transported through the blood, leading to anemia.1
Vitamin Deficiency Tests
Another potential cause for anemia is vitamin deficiency. The doctor may order anemia blood tests to determine the levels of folate and vitamin B-12. Vitamin B-12 and folate are required for proper red blood cell formation. A deficiency will lead to decreased production of normal red blood cells and formation of abnormally large red blood cells with limited ability to bind oxygen.3
Fecal Occult Blood Test
Another potential cause of anemia is excessive bleeding. The fecal occult blood test determines if there is blood in the stool. A sample of stool is placed on a chemically treated card and a solution is applied afterward. If the card turns blue, blood is present in the sample.1
A variety of methods are used to identify sickle cell anemia. These include hemoglobin electrophoresis, fractionation by HPLC and isoelectric focusing.4 These techniques isolate the various types of hemoglobin present in the blood sample and determine their concentrations. The abnormal sickle shaped red blood cells are caused by the hemoglobin variant, Hb S. Positive tests for sickle cell anemia reveal a significant percentage of Hb S in the total hemoglobin.4
1. http://www.anemia.org/patients/faq/ "Frequently Asked Questions." National Anemia Action Council. 9 Feb. 2009. Web. 2 May 2010.
2. http://www.nlm.nih.gov/medlineplus/ency/article/003490.htm Gersten, Todd. "Ferritin." Medline Plus. 28 Jan. 2010. Web. 2 May 2010.
3. http://www.labtestsonline.org/understanding/conditions/vitaminb12.html "Vitamin B12 and Folate Deficiency." Lab Tests Online. American Association for Clinical Chemistry. 6 Mar. 2010. Web. 2 May 2010.
4. http://www.labtestsonline.org/understanding/analytes/sickle/test.html "Sickle Cell Tests." Lab Tests Online. American Association for Clinical Chemistry. 30 Mar. 2010. Web. 2 May 2010.