RBC Count Overview
A red blood cell (RBC) count is one component of the complete blood count (CBC). The CBC is often requested by physicians during a routine physical examination or as a pre-surgical procedure, to assess the health condition of an individual. As part of the test, the RBC count indicates if the patient has normal, increase or decrease number of RBC in his bloodstream. The changes in number are frequently interpreted in relation to the values of other RBC indices, hematocrit and hemoglobin, which are also found in the result of the test.
The RBC count test may be performed several times to patients with polycythemia vera, chronic anemias, hematologic disorders and other bleeding problems. Patients who are in given chemotherapy and radiotherapy may also need to have ther RBC count monitored regularly.
A CBC procedure does not really need any preparation, and the test is often done in an easy and fast manner. An adequate sample of blood is usually taken from a vein in the arm. The area surrounding the vein is often cleansed first with antiseptic. Then, pressure is applied on the arm by wrapping an elastic band or tourniquet to make the blood pool in the vein. After which, the needle is pushed into the vein gently and blood is then withdrawn and placed in an airtight test tube. The tourniquet is then removed. If several tests are ordered, more than one vial of blood are usually taken. As soon as the needed amount of blood is obtained, the needle is removed, and the puncture site is covered to stop any bleeding.
Interpretation of Results
The normal RBC count generally varies with age and gender. In children, the normal RBC count is 4.6 up to 4.8 million/uL. For women the normal is 4.2 up to 5.4 million/uL and for the men, it is 4.7 up to 6.1 million/uL. Variation in the number of RBC can indicate certain medical conditions.
An RBC count below normal may indicate conditions like chronic inflammation, trauma or injury, metabolic disorders, burns, pregnancy, vitamin B12 deficiency, hemorrhagic infection, damage in the bone marrow, hemolytic anemia, iron deficiency anemia, vascular bleeding and bleeding in the gastrointestinal tract. The decrease in its number may also be a result of either a rapid or acute blood loss, or due to undiagnosed chronic or long term loss of blood.
On the other hand, an increase in the number of RBC in the blood may appear in certain medical conditions like renal problems, congenital heart disease, polycythemia vera, pulmonary diseases, over-transfusion of blood, dehydration and hypoxia.
Certain drugs can also alter the number of RBC and these include chemotherapy drugs, qiunidine and chloramphenicol.
Doctors may also request for other specific tests, such as blood chemistry, antibody testing, and urinalysis, together with the CBC and RBC count, depending on his differential diagnosis and the state of health of the patient.
Lab Tests Online: Red Blood Cell Count
MedLinePlus: RBC Count