Complete Blood Count
A Complete Blood Count test CBC is a diagnostic test to measure the following in blood - the number of red blood cells, the number of white blood cells, Platelets and the total amount of hemoglobin in blood. Hematocrit (HCT) is the fraction of blood composed of red blood cells.
A Complete Blood Count normally includes the following components:
A CBC test provides information on measurements such as average red blood cell size or MCV, Hemoglobin per blood cell or Mean Corpuscular Hemoglobin MCH, hemoglobin concentration or the amount of hemoglobin relative to the size of the cell, per red blood cell or MCHC and platelet count.
Why Complete Blood Count test?
This is a complete lab test and is used to detect or monitor different health conditions. A doctor may require this test for various reasons: As a routine check up
If the patient exhibits symptoms such as fatigue, weight loss, fever or any other signs of infection, weakness, bruising, bleeding or signs of cancer
Blood count results may change if you are receiving treatment for medicines and radiation
To monitor any chronic health problem that can change your blood count results such as chronic kidney disease.
Results of CBC
Though blood count may vary with altitude, in general the normal ranges are given below. But it should be noted that these ranges may vary slightly from one laboratory to another. Various laboratories use varied measurements or test different samples. It is best to have it interpreted by a health care provider.
Red blood cell indices:
MCV (Mean Corpuscular Volume): 80 to 95 femtoliter
MCH (Mean Corpuscular Hemoglobin): 27 to 31 pg/cell
MCHC (Mean Corpuscular Hemoglobin Concentration): 32 to 36 gm/dL
RBC (erythrocyte) count:
Male: 4.7 to 6.1 million cells/mcL
Female: 4.2 to 5.4 million cells/mcL
WBC (leukocyte) count:
4,500 to 10,800 cells/mcL
Male: 40.7 to 50.3%
Female: 36.1 to 44.3%
Male: 13.8 to 17.2 gm/dL
Female: 12.1 to 15.1 gm/dL
Platelet (thrombocyte) count:
150,000 to 450,000/dL
What abnormal results mean?
An abnormal result means elevated RBC, hemoglobin or Hematocrit. These may be due to various factors including lack of adequate water and fluids due to severe diarrhea, excessive sweating or if diuretics are used to treat hypertension.
Low RBC, hemoglobin or hematocrit is also a sign of which result due to blood loss on account of heavy menstrual periods over long periods of time, bone marrow failure from radiation, infection or tumor, Hemolysis or breakdown of red blood cells, chronic kidney disease, ulcerative colitis or rheumatoid arthritis, leukemia, multiple myeloma, long term infections such as hepatitis, poor diet and nutritional deficiencies of iron, Vitamin B6, Vitamin B12 and folate.
High levels of Hematocrit can be the result of dehydration, diarrhea, erythrocytosis or myeloproliferative disorders such as Polycythemia Vera.
Lower than normal white blood cell count, or Leukopenia (Leucopenia), can be the result of alcohol abuse and liver damage, autoimmune diseases, bone marrow failure due to infection, tumor, radiation or fibrosis, chemotherapy medicines, disease of liver or spleen, enlarged spleen, infections caused by viruses such as AIDS or medications.
High WBC count is called leukocytosis which can result from certain medicines such as corticosteroids, infections, diseases such as rheumatoid arthritis or allergy, leukemia and severe emotional and physical stress, tissue damage
High platelet count may be due to bleeding - diseases such as cancer, iron deficiency, problems with the bone marrow.
Low platelet count may be due to anemia, disorders where platelets are destroyed during pregnancy, enlarged spleen, bone marrow failure (for example, due to infection, tumor, radiation, or fibrosis), Chemotherapy medicines used to treat cancer.
Disease of the platelets is known as Thrombocytopathy, which could be due to lower Platelet counts (a condition called as Thrombocytopenia or Thrombopenia), or due to a decrease in function (called as Thrombasthenia) or an increase in the number of platelet (addressed as Thrombocytosis). Normal platelet counts do not necessarily indicate normal functioning. In some cases the platelet counts may appear normal but the platelets themselves are dysfunctional. Aspirin inhibits cyclooxygenase-1 (COX1) which results in the disruption of platelet function affecting coagulation. Normal platelet function will be restored only when the affected platelets have been replaced which can take a week.
Precaution : At the time of drawing the blood, it is necessary to clean the venipuncture site with alcohol.
Hemoglobin A1c test
Heart disease is a common complication for diabetes patients. For an early assessment of diabetes and also to detect risk of developing heart disease, the American Diabetes Association recommend Hemoglobin A1c test.
High blood glucose (sugar) levels over time can lead to increased deposits of fatty materials on the insides of blood vessel walls. These deposits may affect blood flow, which increases the chance of clogging and hardening of blood vessels and leads to heart disease. Hemoglobin A1c test reflects blood sugar levels. If non-diabetic, the test result would be around 5%. Diabetic persons aim for a score of 7% or lower. However, the health care provider would discuss the most appropriate target that is individual specific.
In general, if the test score is 8% or more, it indicates necessary changes in diet, exercise and medicines in order to manage the glucose levels. Higher A1C level, poorer blood sugar control and higher is the risk of diabetes complications. As the level rises above 6.5%, correspondingly the risks rise.
The Hemoglobin A1c test is a measure of blood sugar control over the past 2 to 3 months. There is a valid reason for specifically measuring it for the last three months. The life of red blood cells (which is measured as part of the test) is three months. By measuring this part, a good indication of the average blood glucose over the previous 2-3 months can be obtained.
The lab test can be done in two ways, a quick finger stick or a sample of blood from vein. Compared to other tests for measuring blood glucose levels, Hemoglobin A1c test is preferred to assist in predicting the risks of coronary heart disease among diabetes.
Anemia stands for 'without blood' in Greek; When the number of red blood cells (RBC) falls below normal, Anemia is a resultant condition. Hemoglobin is an important constituent of RBC. Hemoglobin usually occurs in the range of 12 and 18 g/dL (grams per deciliter of blood). If the hemoglobin levels show a decrease, anemic conditions set in. Consequently, the various organs and tissues of the body do not receive adequate oxygen on account of the diminished oxygen carrying capacity of the blood. This impairs their normal functioning. Usually women have smaller stores of iron than men. Besides, they also lose blood during menstruation making them primary targets for anemia.
World Health Organization (WHO) defines anemia as a hemoglobin level lower than 13 g/dL in men and lower than 12 g/dL in women. It is essential to be familiar with the typical symptoms of anemia. Often anemia is misdiagnosed and left untreated. An anemic person is likely to feel extremely tired and weak. This is accompanied with dizziness and breathlessness. A person suffering from anemia tends to appear pale and experience feelings of depression. In some cases, anemia can lead to heart ailments too.
Causes of Anemia
Types of Anemia
Iron deficiency Anemia - Nearly 20% adult women tend to suffer from this form of anemia. Loss of blood due to menstruation is not compensated with an iron-rich diet. Pregnancy and breast feeding can also deplete iron stores. Iron deficiency anemia is also noticed during growth spurts or internal bleeding.
Aplastic anemia - When the bone marrow does not produce sufficient quantities of blood cells, aplastic anemia is noticed. Childhood cancers such as leukemia are often responsible for this form of anemia. Other possible causes of aplastic anemia are radiation, cancer or antiseizure medications and chronic diseases such as thyroid or kidney malfunction. Treatment for aplastic anemia involves blood transfusions and bone marrow transplant. This is done to replace malfunctioning cells with healthy ones.
Vitamin deficiency anemia - Low levels of folic acid lead to faulty absorption of iron. Anemia caused due to folic acid deficiency is called Megaloblastic anemia. Pregnancy doubles the body requirements of folic acid and it is imperative that pregnant women take folic acid supplements. Good dietary sources of folate are fresh fruits, green leafy vegetables, cruciferous vegetables, liver and kidney, dairy products and whole grain cereals. Vegetables should be eaten raw or lightly cooked.Folic acid anemia is also a common problem faced by alcoholics. Vitamin B-12 deficiency can lead to a condition of Pernicious anemia. Diseases such as thyroid malfunction or diabetes mellitus can affect the body's ability to absorb vitamin B-12. This vitamin is vital in the production of hemoglobin.
Vitamin C Deficiency Anemia is a rare form of Anemia that is the result of small red cells owing to prolonged dietary deficiency of the Vitamin C.
Sideroblastic Anemia: In this anemia, the body has sufficient iron but it fails to incorporate it into hemoglobin.
Hemolytic Anemia results from high rate of destruction of Red Blood Cells (RBC) at a rate faster than the rate bone marrow can replenish them.
Thalassemia anemia - Thalassemia or Cooleys Disease is a hereditary disorder found predominantly in people of South East Asian, Greek and Italian racial groups. This form of anemia is seen in differing degrees as Thalassemia encompasses a group of related disorders that affect the human body in similar ways. The most common occurrences of Thalassemia are alpha and beta thalassemia. Thalassemia anemia is characterized by symptoms like jaundice, enlarged spleen, shortness of breath and facial bone deformities.
A complete blood count test will test for hemoglobin levels and display an anemic condition. But often anemia is a symptom whose cause lies deeper. The cause and type of anemia will determine the treatment that is needed. A stool test will help in detecting occult blood. Hemoglobin electrophoresis is a blood test that helps identify abnormal hemoglobins. Diagnosing thalassemia or sickle cell anemia becomes possible with this test.
Deficiency can be treated with supplements of iron, Vitamin B-12 and Vitamin C. Partaking an iron-rich diet can be beneficial for those suffering from nutritional deficiency anemia. Seafood, nuts, whole grains and dried fruits such as raisins, prunes and apricots are rich in iron. Ensure adequate consumption of Vitamin C as it aids and stimulates iron absorption. Try and combine citrus foods with iron-rich foods - add tomatoes to a turkey sandwich or chopped strawberries with iron-fortified breakfast cereals.
Bibliography / Reference
Collection of Pages - Last revised Date: March 23, 2019