Increased In:

MCV

• Alcoholism (vitamin deficiency related to malnutrition)
• Antimetabolite therapy (the therapy inhibits vitamin B₁₂ and folate)
• Liver disease (complex effect on RBCs that includes malnutrition, alterations in RBC shape and size, effects of chronic disease)
• Pernicious anemia (vitamin B₁₂/folate anemia)

MCH

• Macrocytic anemias (related to increased hemoglobin or cell size)

MCHC

• Spherocytosis (artifact in measurement caused by abnormal cell shape)

RDW

• Anemias with heterogeneous cell size as a result of hemoglobinopathy, hemolytic anemia, anemia following acute blood loss, iron-deficiency anemia, vitamin- and folate-deficiency anemia (related to a mixture of cell sizes as the bone marrow responds to the anemia and/or to a mixture of cell shapes due to cell fragmentation as a result of the disease)

Decreased In:

MCV

• Iron-deficiency anemia (related to low hemoglobin)
• Thalassemias (related to low hemoglobin)

MCH

• Hypochromic anemias (related to low hemoglobin)
• Microcytic anemias (related to low hemoglobin)

MCHC

• Iron-deficiency anemia (the amount of hemoglobin in the RBC is small relative to RBC size)

RDW:

• N/A