Along with these tests, the RBC count can not only help diagnose disorders that cause too many or too few red blood cells but also offer clues as to what may be causing the problem.

Sickle cell disease (SCD) is a group of inherited RBC disorders in which RBCs become hard, sticky, and sickle-shaped.

RBC indices such as mean corpuscular volume, mean corpuscular hemoglobin concentration, ... inherited RBC disorders, or as a response to drugs or other toxins: Howell-Jolly Bodies ...