Reticulocyte Count

Written by Amber Erickson Gabbey
Medically Reviewed by George Krucik, MD

What Is a Reticulocyte Count

Reticulocytes are immature red blood cells. A reticulocyte count (also known as a retic count, reticulocyte index, or corrected reticulocyte) is a measurement and percentage of how many reticulocytes are in the blood. This count indicates whether enough red blood cells are being produced in the bone marrow.

If the red blood cell count is either too low or too high, the body will attempt to maintain balance by producing and releasing either more or less reticulocytes. Your doctor can tell whether your body is creating and releasing these red blood cells properly by assessing how many red blood cells are in the blood.

Too few red blood cells, either from acute or chronic bleeding, can lead to anemia. Too many red blood cells could be a sign of bone marrow disorders or a vitamin deficiency. It could also be a result of radiation or chemotherapy. While the reticulocyte count does not diagnose anything, it is the first step to identifying where the issue is stemming from.

Why Measure Reticulocyte Counts?

Most commonly, your doctor will recommend a reticulocyte count if he or she wants to assess the functioning of your bone marrow, or to see if the marrow is producing enough red blood cells. Another reason to do a reticulocyte count is to diagnose and distinguish between different types of anemia. Reticulocyte counts may also be used to help monitor progress after chemotherapy, bone marrow transplants, or after treatment for iron deficiency anemia.

Reticulocyte Count Process: What to Expect

Before the Test

Reticulocytes are counted through a blood draw. The process of taking a blood sample for testing is called venipuncture. You may need to fast (refrain from eating or drinking) for a specific period before the blood test. Ask your doctor about any specific pre-test considerations.

Tell your doctor if you have hemophilia, a history of fainting, or any other condition before having this test.

The Test

During the test, your doctor will take blood from a vein, usually from the inner elbow or back of the hand. First, your doctor will sterilize the area with an antiseptic. Then, he or she will wrap a plastic band around your arm to apply pressure and to help the vein swell with blood.

Once the vein swells, your doctor will insert a sterile needle directly into the vein. The blood will collect into an attached vial. Once enough blood has been collected for the sample, the plastic band is untied and the needle is removed from the vein. The site of the needle insertion will be cleaned and bandaged, if necessary.

Some individuals experience only slight pain from the needle prick, while others may feel moderate pain, especially if the vein is difficult to locate. It is common for the spot to throb after the procedure. Some bleeding is also common, as the needle will break the skin. For most people, bleeding is slight and will not cause any issues.

Infants and Young Children

For infants or young children, the testing process may be different. The doctor may instead make a small cut to allow blood to come to the surface. A test strip or slide will then be used to collect a small sample of blood. The area will be cleaned and bandaged if necessary.

Alternative Testing Methods

In some cases, a simple finger prick will suffice for blood testing. In this case, your finger will be pricked with a needle. When the blood comes to the surface, your doctor will collect a sample and then clean and bandage the finger.

What Do the Test Results Mean?

Normal levels of reticulocytes vary due to differing laboratory procedures and levels of hemoglobin in the blood, which could change slightly due to bleeding. Pregnancy and living in high altitudes may also alter the amount of reticulocytes in the blood. Your doctor is looking for a stable percentage and number of reticulocytes in the blood. He or she can then assess the bone marrow functioning from this percentage.

High reticulocyte levels could indicate:

  • acute bleeding
  • chronic blood loss
  • hemolytic anemia
  • kidney disease
  • Erythroblastosis fetalis, also called hemolytic disease (a potentially fatal blood disorder in a fetus or newborn)

Low reticulocyte levels could indicate:

  • iron deficiency anemia
  • folic acid deficiency
  • aplastic anemia
  • radiation therapy
  • cirrhosis of the liver
  • kidney disease
  • vitamin B12 deficiency
  • bone marrow failure (caused by drug toxicity, an infection, or cancer)

More tests may be administered to determine if reticulocyte count is considered abnormal.

Was this article helpful? Yes No

Thank you.

Your message has been sent.

We're sorry, an error occurred.

We are unable to collect your feedback at this time. However, your feedback is important to us. Please try again later.

Article Sources:

More on Healthline

Common Asthma Triggers and How to Avoid Them
Common Asthma Triggers and How to Avoid Them
Learn about some of the most common triggers for asthma, as well as measures you can take to minimize your risk of exposure, symptoms, and flares.
Lifestyle Changes to Help Manage COPD
Lifestyle Changes to Help Manage COPD
Leading a healthy lifestyle can make a big difference in your COPD symptoms. Learn more about basic changes that will make it easier to manage your COPD.
Seasonal Allergies and COPD: Tips to Avoid Complications
Seasonal Allergies and COPD: Tips to Avoid Complications
For COPD patients, allergies pose the risk of serious complications. Learn some basic tips for avoiding allergy-related complications of COPD in this slideshow.
Easy Ways to Conceal an Epinephrine Shot
Easy Ways to Conceal an Epinephrine Shot
Learn how to discreetly carry your epinephrine autoinjectors safely and discreetly. It’s easier than you think to keep your shots on hand when you’re on the go.
Numbness, Muscle Pain and Other RA Symptoms
Numbness, Muscle Pain and Other RA Symptoms
The symptoms of RA are more than just joint pain and stiffness. Common symptoms include loss of feeling, muscle pain, and more. Learn more in this slideshow.
Advertisement
Advertisement
Advertisement