Red Blood Cell Count is a blood test that measures red blood cell count levels in the blood. Normal range: Men: about 4.5-6.5 x10^12/L · Women: about 3.8-5.8 x10^12/L (Australian reference range). The red blood cell count moves together with haemoglobin and haematocrit and is interpreted alongside them rather than in isolation.. It is commonly used to helps assess oxygen-carrying capacity and screen for conditions affecting red blood cell production or survival..
What is Red Blood Cell Count?
The total number of red blood cells per volume of blood.
Why is it measured?
Helps assess oxygen-carrying capacity and screen for conditions affecting red blood cell production or survival.
Normal Reference Range
Men: about 4.5-6.5 x10^12/L · Women: about 3.8-5.8 x10^12/L (Australian reference range). The red blood cell count moves together with haemoglobin and haematocrit and is interpreted alongside them rather than in isolation.
Note: Reference ranges may vary between laboratories. Always consult your healthcare provider for interpretation.
What Causes High RBC?
A high red blood cell count thickens the blood. The most common cause is dehydration (a temporary, concentration effect). Sustained elevation comes from chronic low oxygen — smoking, lung disease, sleep apnoea, altitude — testosterone or EPO use, or the bone marrow disorder polycythaemia vera, and increases clotting risk.
What Causes Low RBC?
A low red blood cell count indicates anaemia. The causes mirror those of low haemoglobin: iron, vitamin B12 or folate deficiency, blood loss, the anaemia of chronic disease, kidney disease, haemolysis, and inherited disorders such as thalassaemia. It can also appear low when blood is diluted by intravenous fluids or in pregnancy.
How Often Should RBC Be Tested?
The red blood cell count is reported in every full blood count, measured at routine check-ups and whenever anaemia or polycythaemia is investigated. It is monitored alongside haemoglobin during treatment and in men on testosterone therapy.
Related Blood Markers
The red cell count is interpreted with haemoglobin and haematocrit, and with the red cell indices (MCV, MCHC, RDW), which classify the type of anaemia. Iron studies, B12 and folate identify nutritional causes.
Key Facts
- •Category: Blood Health
- •Unit of Measurement: 10^12/L
- •Test Code: RBC
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