Red blood cells or erythrocytes carry oxygen from the lungs to the rest of the organs in the human body.
In the CBC, the following erythrocyte measurements are included.
- RBC: The number of red blood cells in your sample.
- Hemoglobin: A protein found in the red blood cells which carries oxygen.
- Hematocrit: The percentage of red blood cells in the total blood volume.
The CBC also includes the following indices which provide information on the physical characteristics of red blood cells:
- MCV (Mean Corpuscular Volume): The mean RBC volume.
- MCH (Mean Corpuscular Hemoglobin): The average hemoglobin amount in each erythrocyte.
MCHC: (Mean Corpuscular Hemoglobin Concentration): A measurement of the concentration of hemoglobin in red blood cells.
- RDW: (Red Cell Distribution Width): The variation of the red blood cells’ size.
Increased values of red blood cells
- Dehydration
- Smoking
- High altitude
- Hereditary cardiovascular disease
- Chronic obstructive pulmonary disease
- Pulmonary fibrosis
- Polycythemia vera
- Drugs (gentamycin, methyldopa, anabolic steroids, diuretics)
Decreased values of red blood cells
- Acute or chronic hemorrhage
- Hemolytic anemia
- Aplastic anemia
- Iron deficiency anemia
- Deficiency of vitamins B6 and B12
- Folate deficiency
- Lead poisoning
- Myelodysplastic syndrome
- Multiple myeloma
- Non-Hodgkin’s lymphoma
- Hypothyroidism
- Inflammatory bowel disease
- Rheumatoid arthritis
- Thalassemias
Increased values of MCV (Macrocytosis)
- Megaloblastic anemia
- Alcoholism
- Liver disease
- Hypothyroidism
- Chronic obstructive pulmonary disease
- Myelodysplastic syndrome
- Gestation
- Drugs (antiretroic drugs, methotrexate, chemotherapy drugs)
Decreased values of MCV (Microcytosis)
- Iron deficiency anemia
- Hemoglobinopathies
- Sideroblastic anemia
- Anemia of chronic disease
- Lead poisoning
Increased values of MCH (Hyperchromia)
- Anemia due to B12 or folate deficiency
- Alcohol abuse
- Drugs (heparin, hydroxyurea, methotrexate)
Decreased values of MCH (Hypochromia)
- Iron deficiency anemia
- Thalassemias
- Blood loss
- Celiac sprue
Increased values of MCHC
- Hereditary spherocytosis
- Sickle cell anemia
- Autoimmune hemolytic anemia
- Serious burns
Decreased values of MCHC
- Iron deficiency anemia
- Celiac sprue
- Chronic, small degree blood loss (menorrhagia, peptic ulcers)
Increased values of RDW
- Iron deficiency anemia
- Macrocytic anemia
- Microcytic anemia
- Hemolytic anemia
- Autoimmune diseases
- Myelodysplastic syndrome
*Decreased RDW values are of no clinical significance.
*Red blood cell indices may be falsely elevated in hyperlipidemic patients.
Examples of various types of anemia
■ Normochromic/Normocytic anemia
Decreased RBCs number but normal indices
■ Hypochromic/microcytic anemia
Decreased MCV & MCHC
■ Normochromic/Macrocytic anemia
Increased MCV value and normal MCHC