To evaluate any change in the number of red blood cells in your blood
Red Blood Cell Count
A blood sample taken from a vein in your arm or by a finger-prick (children and adults) or heel-prick (newborns)
Keep well hydrated by drinking fluids one to two days prior to blood collection
This test counts the number of red blood cells (RBC) in a litre of blood. Red blood cells, which are made in the bone marrow, carry oxygen from the lungs to the cells and transport carbon dioxide from the cells to the lungs. Women tend to have lower RBC counts than men, and levels tend to decrease with age. When the value decreases by more than 10% of the expected normal value, the patient is said to be anaemic.
How is the sample collected for testing?
The test is performed on a blood sample taken by a needle placed in a vein in the arm or by a finger-prick (for children and adults) or heel-prick (for newborns).
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
How is it used?
When is it requested?
What does the test result mean?
A high RBC count may indicate congenital heart disease, dehydration, obstructive lung disease, sleep apnoea or bone marrow over-production. A low RBC count may indicate anaemia, bleeding, kidney disease, bone marrow failure (for instance, from radiation or a tumour), malnutrition, or other causes. A low count may also indicate nutritional deficiencies of iron, folate and vitamin B12.
Is there anything else I should know?
Normal decreases in red blood cells are seen during pregnancy as a result of normal body fluid increases that dilute them.
Living at high altitudes causes an increase in RBC counts—this is your body’s response to the decreased oxygen available at these heights.
How are abnormal red blood cell counts treated?
First, your doctor must determine the cause of your abnormal RBC count so that they can prescribe appropriate treatment. Treatment may include a vitamin or mineral supplement, a change in your nutrition, removal of excess red blood cells or replacement with red blood cells from a blood donor. Alternatively it may only require changing your current medication or prescribing a drug to stimulate red cell production in your bone marrow.
Can I test my RBCs at home?
Do diet and nutrition help keep RBCs at healthy levels?
Are there symptoms I should recognise if my RBCs are dangerously low or high?
Tiredness may indicate a low RBC count. Fainting, pallor (loss of normal skin colour), and shortness of breath also can indicate low RBCs, as do dizziness and an altered mental state that may be the result of dehydration.
When the RBC is high it may cause headaches, visual disturbances and a flushed appearance to the skin.
On This Site
Tests: Full blood count (FBC), Haemoglobin, Haematocrit (PCV), Blood Film, Iron Tests, Reticulocyte Count, Vitamin B12 and Folate, Bone Marrow Aspiration and Biopsy, G6PD, Erythropoietin
Conditions: Anaemia, Bone Marrow Disorders, Sickle Cell Anaemia, Thalassemia
Articles: Blood Banking