Red Blood Cell (RBC) Count
What is a Red Blood Cell (RBC) Count?
A red blood cell (RBC) count is a blood test that measures the number of red blood cells in a sample of blood. Red blood cells are the most common type of blood cell and contain a substance called hemoglobin, which transports oxygen throughout the body. A red blood cell count can help determine if a person has anemia, which is a condition that occurs when the body doesn’t have enough red blood cells or hemoglobin.
Preparation for a RBC Count
Most of the time, no preparation is needed for a red blood cell count. Sometimes your doctor may ask you to restrict your diet within 24 hours before the test, or they may ask you to fast (not eat or drink anything) for 8 hours prior to the test. Be sure to let your doctor know if you are taking any medications, such as vitamins or herbal supplements, as these can affect the results of the test.
Procedure for a RBC Count
A red blood cell count is a simple procedure that typically takes about 15 minutes. During the test, a healthcare provider will draw a sample of blood from a vein in your arm or hand, usually by using a syringe or a vial. The sample will then be sent to a laboratory where it will be analyzed for red blood cell count.
Types of Red Blood Cells
Red blood cells have different shapes, sizes, and densities, which are determined by the type of cell they are. The primary types of red blood cells are:
- Erythrocytes: These are the most common type of red blood cell and are typically small and round.
- Erythroblasts: These are larger, immature red blood cells.
- Leukocytes: These are uncommon red blood cells that have a white exterior.
- Macrophages: These are cells that engulf and digest foreign particles to help the body fight infection.
Risks of a RBC Count
A red blood cell count is a safe procedure with minimal risks. The most common risks associated with the test are pain or discomfort when the blood is drawn, as well as a risk of bruising at the injection site.
Why is a RBC Count Done?
A red blood cell count is typically done to help diagnose anemia and other conditions related to red blood cell production and function. It may also be done to monitor the effectiveness of iron or Vitamin B12 replacement therapy.
When Should a RBC Count Be Done?
Your doctor may recommend a red blood cell count if you have symptoms of anemia such as fatigue, paleness, or shortness of breath. It may also be done to monitor the effectiveness of certain treatments or medications.