Routine examination of the individual involves CBC as the most common test being performed .It can be ordered in the healthy individual and also in people with certain signs and symptoms:
CBC examination involves certain basic parameters:
Haemoglobin is the major component of the RBC .It is a type of conjugated protein that helps in the transport of the the oxygen hence it represent the amount of oxygen carrying protein in the blood.
Red Blood cell countIt represent the number of red blood cell present in the blood of the patient .It indirectly also measure the oxygen carrying capacity of the unit of blood
Packed cell volumeAka Haematocrit
It is the ratio of the volume of erythrocytes to that of the whole blood .It is usually expressed as percentage.
Total leucocyte count is the absolute number of the white blood cells (Leucocyte ) present in the unit amount of blood. Leucocyte are involved in the body defence system.
Differential Leucocyte countIt provide information regarding the different type of white blood cells in the blood and it is represented as the percentage on the total leucocyte count. It is also reported as the Absolute differential leucocyte count. It elaborate on the 5 types of the leucocytes present in blood - Neutrophil, Lymphocyte , Monocyte , Eosinophil , Basophil . Each of these cells have specific functions and their percentage varies with different subsets of physiological and pathological response.
Platelet functions are involved in the blood coagulation pathways of human body hence they are key to maintaining the haemostasis and vascular integrity. At times platelet distribution width (PDW) is also reported which reflect the uniformity in the size of the platelet.
Aka erythrocyte indices
These indices are of major importance in sub classifying Anaemia. These are calculated from the red cell count, haematocrit and Haemoglobin concentration. These include:
MCV- It is the average volume of the Red blood cell.
MCH- It is the content of Hb present in the average red blood cell.
MCHC- It is the average amount of Haemoglobin present in the given volume of haematocrit
ESR estimation is usually done separately, but at times it can be part of the CBC examination. It is nonspecific test which highlights the underlying process of inflammation in the body . In recent times it being replaced by C - reactive protein (CRP) estimation.
Decreased (known as Anaemia) -
Increased (known as Polycythaemia) -
Usually represented by values of RBC COUNT
RBC INDICES
MCV
Decreased ( microcytes ) -
MCH-
Correlate with the MCV values and usually
follow same trend.
MCHC-
Decreased-
| Men: |
4.5-5.5 million RBCs per microliter (mcL) |
| Women: |
4.0-5.0 million RBCs per mcL |
| Children: |
3.8-6.0 million RBCs per mcL |
| Newborn: |
4.1-6.1 million RBCs per mcL |
| Men: |
42%-52% |
| Women: |
36%-48% |
| Children: |
29%-59% |
| Newborn: |
44%-64% |
| Men: |
14-17.4 grams per deciliter (g/dL) |
| Women: |
12-16 g/dL |
| Children: |
9.5-20.5 g/dL |
| Newborn: |
14.5-24.5 g/dL |
| Mean corpuscular : |
84-96 femtoliters (fL) |
| volume (MCV)-Adults: | |
| Mean corpuscular hemoglobin (MCH)-Adults: |
28-34 picograms (pg)per cell |
| Mean corpuscular hemoglobin concentration (MCHC)-Adults: |
32-36 grams per deciliter (g/dL) |
| Normal: |
11.5%-14.5% |
| Men and non pregnant women: |
5,000-10,000 WBCs per cubic millimeter (mm3) |
| Neutrophils: |
50%-62% |
| Band neutrophils: |
3%-6% |
| Lymphocytes: |
25%-40% |
| Monocytes: |
3%-7% |
| Eosinophils: |
0%-3% |
| Basophils: |
0%-1% |
