Overview of Complete Blood Count
What is Complete Blood Count?
Preparation for Complete Blood Count
- No special preparation required
Why Get Tested for Complete Blood Count?
To monitor your overall health as part of a routine check-up
To help detect a variety of disorders including infections, anemia, diseases of the immune system, and blood cancers
To monitor an existing blood disorder
To monitor treatment that is known to affect blood cells such as chemotherapy or radiotherapy
Understand more about Complete Blood Count
Blood is composed of blood cells suspended in blood plasma (yellowish coloured liquid). The blood cells include red blood cells (also called RBCs or erythrocytes), white blood cells (also called WBCs or leukocytes) and platelets (also called thrombocytes).
Red blood cells (RBCs) are the most abundant blood cells. RBCs contain the hemoglobin which helps in the transport of oxygen to the tissues. RBC count is a measurement of the number of RBCs in a given volume of blood.
Packed Cell Volume (PCV) or Hematocrit (Hct) is a measurement of the blood volume occupied by RBCs. It is expressed in percentage.
White blood cells (WBCs) are key components of the immune system and thus protect the body from various infections and cancers. Total Leucocyte count (TLC) is a measurement of the total number of leukocytes (WBCs) in a given volume of blood.
There are five types of WBCs:
Differential Leucocyte Count (DLC) determines the percentage of different types of WBCs.
Neutrophils, Basophils, and Eosinophils are called Granulocytes because of the presence of granules inside these cells.
Absolute count of different types of WBCs is the measurement of their absolute numbers in the given volume of blood.
In addition to counting, measuring and analyzing red blood cells, white blood cells and platelets, this test also measure the amount of hemoglobin in the blood and within each red blood cell.
Platelet count - Platelets (also called thrombocytes) are disc-shaped cell fragments without a nucleus that help in blood clotting. Platelet count is a measurement of the number of platelets in a given volume of blood.
Mean Platelet Volume (MPV) is a measurement of the average size of platelets.
Hemoglobin (Hb) - Hemoglobin (Hb) is a protein found in red blood cells (RBCs) that carries oxygen from the lungs to the body tissues, and to exchange the oxygen for carbon dioxide, and then carry the carbon dioxide back to the lungs and where it is exchanged for oxygen. This is the amount of hemoglobin in a given volume of blood.
Mean Corpuscular Volume (MCV) is the average volume of a red blood cell.
Mean Corpuscular Hemoglobin (MCH) is the average amount of hemoglobin in the average red cell.
Mean Corpuscular Hemoglobin Concentration (MCHC) is the average concentration of hemoglobin in a given volume of red cells.
Red Cell Distribution Width (RDW)
is a measurement of the variability of red blood cell size
What Results of Complete Blood Count mean?
The abnormal CBC test results may be interpreted as:
Decreased level of hemoglobin is suggestive of anemia while increased levels are seen in polycythemia (a disorder in which your body makes too many red blood cells). Various causes of anemia are iron deficiency anemia, vitamin B 12 deficiency anemia, hemolytic anemia
High WBC count is associated with infections, inflammatory disorders, leukemia, myeloproliferative disorders while low levels may be seen in aplastic anemia, bone marrow disorders, autoimmune conditions
High neutrophil count (neutrophilia) can be seen in acute bacterial infections, inflammation, burns while lower values (neutropenia) may be seen in aplastic anemia, autoimmune disorders, drug reactions or chemotherapy
High lymphocyte count (lymphocytosis) may be seen in acute viral infections, tuberculosis, lymphocytic leukemia while lower values (lymphopenia) may be seen in bone marrow damage, aplastic anemia, autoimmune disorders
High monocyte count (monocytosis) may be seen in chronic infections like tuberculosis, bacterial endocarditis, collagen vascular disorders, inflammatory bowel diseases while lower values may be seen in bone marrow damage
High eosinophil count (eosinophilia) can be seen in asthma, allergies, drug reactions, parasitic infections, while lower levels are rare and medically insignificant
High basophil count (basophilia) may be seen in chronic myeloid leukemia (CML) while lower levels are medically insignificant
Low platelet counts also called as thrombocytopenia are associated with viral infections like dengue fever, bleeding or platelet disorders
Increased MCV can indicate anemia due to Vitamin B12 or folate deficiency and decreased MCV is seen in iron deficiency anemia.
Hematocrit lower than normal can indicate iron deficiency while a high level can occur in dehydration (loss of water) or other conditions.
Diet, medications, physical activity level, a women's menstrual cycle, and other considerations can affect the test results.
Patient Concerns about Complete Blood Count
Frequently Asked Questions about Complete Blood Count
Tests Included in Complete Blood Count(24 tests)
- Packed Cell Volume
- Differential leucocyte Count(includes 6 tests)
Differential Eosinophil Count
Differential Neutrophil Count
Differential Monocyte Count
Differential Granulocyte Count
Differential Lymphocyte Count
Differential Basophil Count
- Absolute Monocyte Counts
- Red Blood Cell Count
- RDW SD
- Platelet Count
- Total Leucocyte Count
- Red Cell Distribution Width
- Mean Corpuscular Volume
- Mean Corpuscular Hemoglobin
- Mean Corpuscular Hemoglobin Concentration
- Mean Platelet Volume