RBC (varies with altitude):

• male: 4.7 to 6.1 million cells/mcl
• female: 4.2 to 5.4 million cells/mcl

Abnormal RBCs have a shorter-than-normal life span. Trauma within the blood vessels, such as that caused by artificial heart valves or peripheral vascular (blood vessel) disease, can damage RBCs. An enlarged spleen, as can be caused by portal hypertension or leukemia, may remove normal red cells along with aging ones.

Higher-than-normal numbers of RBCs may indicate:

• congenital heart disease
• cor pulmonale
• pulmonary fibrosis
• polycythemia vera
• dehydration (such as from severe diarrhea)
• kidney disease with high erythropoietin production

Lower-than-normal numbers of RBCs may indicate:

• anemia (various types)
• hemorrhage (bleeding)
• bone marrow failure (for example, from radiation, toxin, fibrosis, tumor)
• erythropoietin deficiency (secondary to kidney disease)
• hemolysis (RBC destruction) from transfusion reaction
• leukemia
• multiple myeloma
• malnutrition

nutritional deficiencies of:

• iron
• folate
• vitamin B-12
• vitamin B-6
• overhydration

Additional conditions under which the test may be performed:

• Alport syndrome
• hemolytic anemia due to G6PD deficiency
• idiopathic autoimmune hemolytic anemia
• immune hemolytic anemia
• macroglobulinemia of Waldenstrom
• paroxysmal nocturnal hemoglobinuria (PNH)
• primary myelofibrosis
• renal cell carcinoma
• drug-induced immune hemolytic anemia
• congenital anemias, such as thalassemia