Red Blood Cell (RBC) Indices

Red blood cell (RBC) indices measure your red blood cells' size, shape, and quality. Red blood cells are also known as erythrocytes. They are made in your bone marrow (the spongy tissue inside your large bones).

They contain hemoglobin, an iron-rich protein in your red blood cells that carries oxygen from your lungs to every cell in your body. Your cells need oxygen to grow, reproduce, and make energy. Knowing the size and shape of your red blood cells can help your provider determine if you have a certain type of anemia, a condition in which your body does not make enough healthy red blood cells.

There are four types of red blood cell indices: Mean corpuscular volume (MCV), which measures the average size of your red blood cells.; Mean corpuscular hemoglobin (MCH), which measures the average amount of hemoglobin in a single red blood cell.; Mean corpuscular hemoglobin concentration (MCHC), which measures how concentrated (close together) the hemoglobin is in your red blood cells. It also includes a calculation of the size and volume of your red blood cells.; Red cell distribution width (RDW), which measures differences in the volume and size of your red blood cells. Healthy red blood cells are usually about the same size.; If one or more of these indices are not normal, it may mean you have some type of anemia.

Why this test is done

You may get this test as part of a complete blood count, which is often included in a routine checkup. You may also need this test if you have symptoms of anemia, which may include:

• Shortness of breath
• Weakness or fatigue
• Headache
• Dizziness
• Arrhythmia (a problem with the rate or rhythm of your heartbeat)
• Pale skin
• Cold hands and feet

How to prepare

You don't need any special preparations for a red blood cell (RBC) indices test.

Sample type

Blood

Other names for this test

erythrocyte indices