Anemia is normally tested and confirmed by a complete blood cell (CBC) count. After a general check-up, a physician usually orders for the CBC test. Only after the CBC and on the basis of clinical reports and symptoms, it is determined whether a person is anemic or not.
Therefore, the CBC is the key to move forward. A CBC is a test for counting and examining the different types of cells in the blood. Earlier, CBC assessment was done by a physician or a laboratory technician by viewing a glass slide prepared from a blood sample under a microscope. Now, these tests are mostly automated and done by machines. Six parameters of a CBC test are Red blood cell (RBC) count, Hematocrit, Hemoglobin, White blood cell (WBC) count, differential blood count and Platelet count.
For diagnosis of anemia only the first three of these tests namely the red blood cell (RBC) count, the hematocrit, and the hemoglobin are considered relevant.
Moreover, mean corpuscular volume (MCV) is also often reported in a CBC, which essentially measures the average volume of RBC in a blood sample. This is important in distinguishing the causes of anemia. Units of MCV are reported in femtoliters, a fraction of one millionth of a liter.
Level of Hemoglobin is critical in detection of anemia. Hemoglobin is the iron-bearing and oxygen-carrying component of red blood cells. The normal value for hemoglobin varies by age and gender. Anemia is generally considered when hemoglobin concentrations fall below:
11 g/dL for pregnant women
- 12 g/dL for non-pregnant women
- 13 g/dL for men
Mild anemia is considered when hemoglobin is between 9.5 – 13.0 g/dL whereas when hemoglobin is between 8.0 – 9.5 g/dL, it is taken as moderate. Severe anemia is considered for hemoglobin concentrations below 8.0 g/dL.
Hematocrit is the next critical measurement and it is the percentage of blood composed of red blood cells. People with a high volume of plasma (the liquid portion of blood) may be anemic even if their blood count is normal because the blood cells have become diluted. Like hemoglobin, a normal hematocrit percentage depends on age and gender. Anemic ranges for hematocrit are below 39 for adult and below 36 for adult non pregnant women. For adult pregnant women, it is below 33% for being anemic.
Other Iron Status Blood Tests such as Serum Ferritin, Serum Iron are also done to determine the anemic conditions. Ferritin is a protein that binds to iron and helps to store iron in the body. Low levels typically mean reduced iron stores. Normal values are generally 12 – 300 ng/mL for men and 12 – 150 ng/mL for women. Lower than normal levels of ferritin are a sign of iron-deficiency anemia.
Serum iron measures the amount of iron in the blood. A normal serum iron is 60 – 170 mcg/dL. Lower levels may indicate iron-deficiency anemia or anemia of chronic disease, while higher levels may indicate hemolytic anemia or vitamin B12 deficiency.
Sometimes total iron binding capacity (TIBC) is also measured to check the level of transferrin in the blood. Transferrin is a protein that carries iron in the blood. TIBC calculates how much or how little the transferrin in the body is carrying iron. A higher than normal TIBC is a sign of iron-deficiency anemia. A lower than normal level may indicate anemia of chronic disease, sickle cell, pernicious anemia, or hemolytic anemia.