RBC count ranges (Red Blood Cells or erythrocytes) depend on gender and age according to the following table:
Each laboratory must establish its own normal ranges for RBC count in the blood. These ranges depend on the makeup of the local population, the technologies used and the accuracy of the measurement. There may be also slight differences in the normal levels, according to age, gender, race or ethnic origin, geographic region, diet, type of sample and other relevant status.
Your doctor will study the results along with your medical record, screenings, physical condition, symptoms and any other relevant information about your situation.
There are some circumstances that can alter the normal ranges:
RBC (Red Blood Cells), also called erythrocytes, are the cells that carry oxygen from the lungs to the body tissues.
Inside the red blood cells, there is a protein called hemoglobin that can contain iron to bind oxygen molecules and that gives RBC its red color.
Hemoglobin is, ultimately, the responsible to carry the oxygen around the body through the bloodstream and to collect the carbon dioxide away from the tissues and back to the lungs to be breathed out.
RBCs have a biconcave shape and with a mean lifespan of 115 days.
RBC cells are created in the red bone marrow. The erythropoietin hormone, secreted mainly by the kidney, stimulates the production of RBCs by the bone marrow. If there is a lack of oxygen in the cells of the body there will be an increase in erythropoietin hormone production, which finally it will increase the production of RBC by the bone marrow (erythropoiesis).
RBC count is used to know the overall health status, the possible existence of an anemia, a general disease or a cancer.
The RBC count test should be studied for a better diagnosis along with other blood tests such as the hemoglobin, the hematocrit, MCV (Mean Corpuscular Volume), MCH (Mean Corpuscular Hemoglobin) and MCHC (Mean Corpuscular Hemoglobin Concentration).
A low RBC count, called erythrocytopenia, usually comes with a low hemoglobin level in the blood in what is called anemia. There are different types of anemia for example, iron deficiencyanemia (lack of iron), megaloblastic anemia (lack of Vitamin B12 or folic acid) or hemolytic anemia (premature destruction of erythrocytes). Aplastic anemia where the bone marrow does not produce enough new blood cells also cause erythrocytopenia.
Another possibility for a low RBC count is an excessive bleeding (menstruation, etc.) or kidney disorders that may reduce the production of erythropoietin hormone.
The RBC count may be elevated for many pathologic reasons. Erythrocytosis may be:
Respiratory diseases that cause tissue hypoxia increase the secretion of erythropoietin and therefore an increase in RBC.
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The following values are considered to be normal values:
IMPORTANT: These levels are expressed in mill/µl (microliter). They are an example of a healthy woman of about 45 years old with no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.
RBC Count | |||||||
|---|---|---|---|---|---|---|---|
| Normality | |||||||
| 4 mill./µl | 4.1 mill./µl | 4.2 mill./µl | 4.3 mill./µl | 4.4 mill./µl | 4.5 mill./µl | 4.6 mill./µl | 4.7 mill./µl |
| 4.8 mill./µl | 4.9 mill./µl | 5 mill./µl | 5.1 mill./µl | 5.2 mill./µl | 5.3 mill./µl | 5.4 mill./µl | 5.5 mill./µl |