What is a red blood cell count?
Red blood cell count is a blood test used by your doctor to determine how many red blood cells (RBCs) you have. It is also known as erythrocyte count.
Testing is important because RBCs contain hemoglobin, which carries oxygen to your body's tissues. The amount of RBCs you have can affect how much oxygen your tissues receive. Your tissues need oxygen to function.
Symptoms of an abnormal count
If your RBC score is too high or too low, you may experience symptoms and problems.
If you have a low RBC score, symptoms may include:
- fatigue
- shortness of breath
- dizziness, weakness, or lightheadedness, particularly when you change positions quickly
- increased heart rate
- headaches
- pale skin
If you experience these symptoms your
doctor may control the RBC count.
- fatigue
- shortness of breath
- joint pain
- tenderness in the palms of the hands or soles of the feet
- itching skin, particularly after a shower or bath
- sleep disturbance
If you experience these symptoms your doctor may control the RBC count.
Why do I need an RBC count?
According to the American Association for Clinical Chemistry (AACC), the test is almost always part of the complete blood count (CBC) test. CBC testing measures the amount of all substances in the blood, including:
- red blood cells
- white blood cells
- hemoglobin
- hematocrit
- platelets
Your hematocrit is the amount of red blood cells in your body. A hematocrit test measures the amount of RBCs in your blood.
Platelets are tiny cells that circulate in the bloodstream and form blood clots that allow wounds to cool down and prevent excessive bleeding.
Your doctor may order a test if he or she suspects you have a condition affecting your RBCs, or if you are showing signs of low blood pressure. These may include:
- bluish discoloration of the skin
- confusion
- irritability and restlessness
- irregular breathing
The CBC test will be part of a standard physical exam. It can be an indicator of a lifetime. It can also be done before surgery.
If you have a diagnosed blood condition that may affect the RBC count, or are taking any medications that affect your RBCs, your doctor may order a test to monitor your condition or treatment. Physicians can use CBC tests to monitor conditions such as leukemia and blood infections.
How is the RBC count performed?
RBC number is a simple blood test done at your doctor's office. You doctor will draw blood from your vein, usually inside your elbow. The steps involved in drawing blood are:
- The health care provider will clean the disinfectant.
- They will wrap a stretch band around your upper arm to make your vein swell with blood.
- They will carefully insert the needle into your vein and collect the blood in a vial or tube attached.
- They will then remove the needle and elastic band from your arm.
- The health care provider will send a sample of your blood to the laboratory for analysis.
How should I prepare for the RBC count?
Usually no special preparation is required for this test. But you should tell your doctor if you are taking medication. This includes any over-the-counter (OTC) medications or supplements.
Your doctor will be able to tell you about any other precautionary measures needed.
What are the risks of getting an RBC count?
As with any blood test, there is a risk of bleeding, injury, or infection in the piercing area. You may feel moderate pain or a sharp sensation when the needle enters your arm.