Difference Between RBC and WBC

The difference between RBC and WBC is mainly due to the following properties like:
Colour: As the name, red blood cell and white blood cell itself clears the colour difference, but the reason behind the red colour of RBC is due to the iron atom present in the haemoglobin pigment. The white blood cells are colourless because of the reason that these lacks any coloured pigment.
Morphology: The structure of red blood and white blood cell have a characteristic shape. Red blood cells resemble a shallow bowl by having flattened centre and elevated margin. White blood cells look like the amoeboid cells by having an irregular margin.

Function: Both red blood and white blood cells belong to the circulatory system where one facilitates the gaseous exchange between the cardiovascular system and the other provides resistance against the infection and pathogen attack.

Content: RBC Vs WBC

  1. Comparison Chart
  2. Definition
  3. Key Differences
  4. Similarities
  5. Conclusion

Comparison Chart

PropertiesRBC WBC
Stands forRed Blood CellWhite Blood Cell
Alternative nameErythrocytesLeukocytes
ShapeBiconcave, disc-likeIrregular, amoeboid-like
Diameter7.5 µm15 µm
ColourRed coloured due to haemoglobin pigmentColourless and does not contain such pigment molecules
Method of productionErythropoiesisLeucopoiesis
Regulatory hormoneErythropoietin hormoneLeucopoietin hormone
OriginationBone marrowBone marrow, lymph nodes, spleen etc.
Life span100-120 days12-20 days
Constitution in blood36-50%Around 1%
Circulatory movement Moves between the cardiovascular systemMoves between the cardiovascular and lymphatic system
Cell count/µl of blood4.7-6.1 million/µl4500-11000/µl
When cell count increasesLeads to PolycythaemiaLeads to Leukocytosis
When cell count decreasesLeads to anemiaLeads to Leukopenia
MeasurementCan be measured by using haemocytometer via RBC pipetteCan be measured by using haemocytometer via WBC pipette
Number incrementsCell count of RBCs increases by the uptake of iron-rich food, doing exercise etc.Cell count of WBCs increases by any kind of foreign attack
TypesIt has no subtypesThese are of five kinds: neutrophil, eosinophil, basophil, lymphocytes and monocytes
Functional roleHelps in circulation of oxygenated blood and nutrients throughout the bodyProvides protection against the pathogens and removes the infected cells via phagocytosis

Definition of RBC

RBC is an abbreviation of the term “Red Blood Cell”. It can define as the component of blood and a type of blood cells that originate from the bone marrow, attains maturity for at least seven days and finally releases into the bloodstream for the transportation of O2 and CO2 into and out of the body. The formation of red blood cells are regulated by a hormone “Erythropoietin” produced primarily by the juxtaglomerular cells of the kidney and the process refers as “Erythropoiesis”.
red blood cells
An immature RBCs commonly refers to as “Reticulocytes”, and a mature RBCs refers as “Erythrocytes”. A structure of mature RBC lacks a nucleus and other cell organelles like ribosomes, mitochondria etc. and can modify its shape. By the movement of red blood cells in the bloodstream, it can flexibly pass through the small blood vessels and capillaries.

It also refers as “Red cells” because of its red colour that is due to the presence of protein pigment “Haemoglobin”. Haemoglobin is an oxygen-carrying pigment, which contains four iron atoms that will bind to the four oxygen molecules. Therefore, haemoglobin is the major component of red blood cell that not only imparts a red colour but also facilitates the transportation of oxygenated blood from the lungs to the other body parts and carbon dioxide from the other body parts back into the lungs.

Mutation in the haemoglobin gene can cause abnormal disease like sickle cell anaemia, where the oval shape of RBCs changes to sickle-like. The volume of RBC measures in terms of a unit called “Haematocrit” and the method of determining RBC ratio in the blood known as “Haematocrit test”. The process of maintaining a concentration of RBCs in the blood commonly refers to as “Homeostasis”, where the degradation and production occur at the same rate.

Definition of WBC

WBC is an abbreviation of the term “White Blood Cell”. It can define as the component of blood and a type of blood cells that also originate from the bone marrow and then matures in the organs like lymph nodes, spleen and thymus gland. The production of white blood cells are regulated by a hormone “Leucopoietin” that stimulate the production of myeloid cells, and the process refers to as “Leucopoiesis”.
white blood cells
Based on cell lineage, leukocytes classify into myeloid and lymphoid cells. A myeloid stem cell produces monocytes and myelocytes (Neutrophils, eosinophils and basophils), while a lymphoid stem cell produces lymphocytes.

Similarly, based on the presence of specific cytoplasmic granules, leukocytes classify into granulocytes and agranulocytes. The granulocytes involve neutrophils, eosinophils and basophils that comprises of distinct granules in their cytoplasm. In contrast, non-granulocytes include monocytes and lymphocytes, which consist of non-distinct or non-functional granules.
types of WBCs
Neutrophils: These are the phagocytic cells that activate against acute infection appeared due to bacterial and fungal attack.
Eosinophil: These stimulate in counter to any parasitic infections.
Basophils: These cells mainly activate against some allergic reactions, especially in the case of type-1 hypersensitivity.
Monocytes: It primarily presents the antigenic fragments to the T-cell and activates against the chronic infection.
Lymphocytes: These are of two kinds, where the B-lymphocytes produce antibodies to neutralize the antigenicity or blocks the pathogen invasion and T-lymphocytes activates in counter to the viral and chronic infection.

Key Differences Between RBC and WBC

  1. Erythrocytes, red cells or red blood corpuscles are the alternative names for RBC, and leukocytes, white cells or white blood corpuscles are the alternative names for WBC.
  2. The diameter or size of the RBCs is much smaller (7.5 µm) comparative to the width of WBCs (15 µm).
  3. A structure of RBC lacks nucleus or “Anucleated”, where WBC contains a distinct nucleus or “Nucleated”.
  4. The RBCs have a life span of about 100-120 days whereas WBCs have a life span of about 12-20 days.
  5. Red blood cells constitute about 36-50% of the total blood, while white blood cells make about 1% of the total blood.
  6. The circulatory movement of RBC is between the cardiovascular system, whereas WBC moves between the cardiovascular and lymphatic system.
  7. A normal range of RBC in per microliter of blood sample is between 4.7-6.1 million and when the cell count increases and decreases, it turns into a medical condition known as Polycythaemia and Anaemia respectively. A normal range of WBC in per microliter of blood sample is between 4500-11,000 and when the cell count increases and decreases, it turns into a medical condition known as Leukocytosis and Leukopenia respectively.


  1. Both RBC and WBC are the kinds of blood cells that are the universal constituents of blood.
  2. Haematocrit test is a complete blood count test that can measure the cell concentration of RBC (represented as haematocrit) and the concentration of WBC (represented by the Buffy layer).
  3. Both are the kind of blood cells produced by the haematopoietic stem cells, and the process commonly refers as haematopoiesis.
  4. The cell number of both red blood and white blood cells can be determined by using a Neubauer counting chamber or haemocytometer under the microscope.


Therefore, we can conclude that RBC and WBC being a part of the circulatory system performs distinct functions to boost up the body’s immunity and metabolism.

1 thought on “Difference Between RBC and WBC”

  1. Comparison about red blood cells and white blood cells, is too good information for me and other people’s. You provided great information about this.

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