Final answer:
A reticulocyte count measures the percentage of immature red blood cells in the bloodstream and provides information about red blood cell production.
Step-by-step explanation:
A reticulocyte count is a test that measures the percentage of immature red blood cells, known as reticulocytes, in the bloodstream. Reticulocytes are released from the bone marrow and mature into erythrocytes, or red blood cells. By measuring the number of reticulocytes, doctors can gain insight into the rate of red blood cell production. Abnormally low or high reticulocyte counts can indicate problems with the production of red blood cells.