Red Blood Cell Count: Normal Range, Symptoms, Indications, Interpretation, Interfering Factors and Treatment

Red Blood Cell Count or RBC Count

Red Blood Cell Count or RBC Count

Red Blood Cell Count

● Red blood cell count or RBC Count measures the number of red blood cells.

● Red blood cell (RBC) count is almost always part of a complete blood count.

● RBC counts help diagnose different kinds of anemia (low number of RBCs) and other conditions affecting red blood cells.

● RBCs or erythrocytes are biconcave-shaped cells.

● RBCs carry oxygen from the lungs to the tissues and carry carbon dioxide from the peripheral tissues to the lung.

● They have a lifespan of 120 days and are removed from the blood by the liver, spleen, and bone marrow, which are a part of the reticuloendothelial system.


● The RBC count is determined by counting the number of red blood cells in a specific volume of blood.

● It is usually measured as the number of RBCs per microliter (μL) or cubic millimeter (mm^3) of blood.

● This measurement is typically obtained through a complete blood count (CBC) test.

Clinical significance:

● The RBC count provides valuable information about the oxygen-carrying capacity of the blood and helps in diagnosing and monitoring various medical conditions.

● It is an important component of the CBC and is often interpreted alongside other blood parameters.

Normal Range of RBC Count

Male Adult: 4.5 – 6.2 million cells/cumm

Female Adult:  4.5 – 5 million cells/cumm

Child, 1 – 18 years: 4.0 – 5.5 million cells/cumm

Infant, 6 – 12 months: 3.5 – 5.2 million cells/cumm

Infant, 2 – 6 months: 3.5 – 5.5 million cells/cumm

Infant, 2 – 8 weeks: 4.0 – 6.0 million cells/cumm

● Newborn: 4.8 – 7.1 million cells/cumm

Symptoms of an abnormal count

Symptoms of a low red blood cell count include:



Pale skin

Rapid heartbeat

Symptoms of a high red blood cell count include:


Shortness of breath

Joint pain



Vision problems

Tenderness in your palms or soles of your feet

Itching skin, particularly after a shower or bath

Sleep disturbance

Indications of RBC Count

To determine anemia, polycythemia, dehydration or response to treatment.

Interpretation of RBC Count

RBCs increase either due to a relative decrease in plasma as in hemoconcentration or dehydration or as a result of an absolute increase in hematopoietic, as in renal cell carcinoma.

A low red blood cell count can be a sign of:


Vitamin B-12 or folate deficiency

Stomach ulcers



Hodgkin lymphoma


Multiple myeloma


Kidney failure

It may also be a sign of pregnancy.

A high red blood cell count can be a sign of:


Heart disease

Polycythemia vera, a bone marrow disease that causes too many red blood cells to be made

Scarring of the lungs, often due to cigarette smoking

Lung disease

Kidney diseases

Blood disorders

Kidney cancer

Interfering Factors

Your RBC count could be affected by:






Some medicines

Your position when the blood is drawn

Clinical considerations:

The RBC count is often evaluated alongside other blood parameters, such as hemoglobin and hematocrit, to gain a comprehensive understanding of blood health.

Trends in RBC count over time, along with the individual’s symptoms and medical history, are important for diagnosis and monitoring of conditions.

Treatment for a low RBC count

All types of anemia require treatment. Your treatment will depend on what’s causing your anemia.

Iron deficiency: You can take iron supplements.

Vitamin deficiency: You can take vitamin supplements.

Bone marrow failure: Your doctor may prescribe certain medications or a bone marrow transplant.

Chronic conditions: focus on treating the underlying condition. Sometimes, prescribe an EPO-stimulating agent.

Blood loss: A blood transfusion can bring in more RBCs to your body.

Treatment for a high RBC count

Erythrocytosis: you may need regular phlebotomy. This removes a small amount of blood from your body in order to lower your RBC count.

Phlebotomies: don’t work, your doctor may prescribe hydroxyurea (Hydrea or Droxia) to reduce your RBC count.

You may also need aspirin to help with potential blood clots.


While RBC count provides valuable information about blood health, it is important to interpret the results in the context of the individual’s overall health, medical history, and additional laboratory findings.

Other blood parameters and clinical assessments are often necessary for a comprehensive evaluation.

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