Reticulocytes (Absolute)

Your bone marrow constantly creates new red blood cells as your body needs them. A reticulocyte count checks to see if your bone marrow is making the right amount of red blood cells when old ones die off. If you have too few, your tissues may not get enough oxygen. If you have too many, you could be at risk for blood clots or other health concerns. This test can check for certain health conditions or show how well a treatment is working.

If the reticulocyte count is too high or too low, it can be a sign of a serious health condition, including anemia and conditions of the bone marrow, liver, and kidneys.

To understand the results of a reticulocyte count test, your provider will consider your symptoms, medical history, and the results of other blood tests.

A higher-than-normal reticulocyte count (reticulocytosis) usually means your bone marrow is making more red blood cells than usual. This often happens after blood loss, after starting treatment for a vitamin or iron deficiency, in conditions where red cells are being destroyed (hemolytic anemia), or at high altitudes.

A lower-than-normal reticulocyte count usually means your bone marrow is not producing enough red blood cells. Causes include iron, vitamin B12, or folate deficiency, bone marrow disorders, kidney disease, chronic illness, and certain medicines or treatments such as chemotherapy or radiation.

When you start iron, B12, or folate treatment for anemia, the reticulocyte count is one of the first numbers to rise, often within days, which is a helpful sign that the treatment is working.

If your reticulocyte test results were not normal, it doesn't always mean you have anemia or another health condition. Talk with your provider about what your results mean for you.