Reticulocytes are an immature form of red blood cells.
Normally, there are very few reticulocytes in the blood. The normal response to anemia or bleeding is increased production and release of reticulocytes, as in:
Iron-deficiency anemia, effectively treated with iron
Pernicious anemia, effectively treated with B12.
Several days after an acute hemorrhage
Hemolytic anemias
The exception to this increase is when the bone marrow is unable to increase production and release of reticulocytes, such as in:
Iron deficiency anemia
Aplastic anemia
Pernicious anemia
Bone marrow tumors
Radiation therapy
Normal Values*
Men
0.5-1.5% of RBCs
Women
0.5-2.5% of RBCs
Children
0.5-4.0% of RBCs
*These are general values taken from a variety of sources. The actual normal values may vary from lab to lab and from one type of testing protocol to another.
Source: Operational Medicine 2001, Health Care in Military Settings, NAVMED P-5139, May 1, 2001, Bureau of Medicine and Surgery, Department of the Navy, 2300 E Street NW, Washington, D.C., 20372-5300