Microcytic anemia

Microcytic anaemia is any of several types of anemia characterized by small red blood cells (called microcytes). The normal mean corpuscular volume (abbreviated to MCV on full blood count results) is 76-100 fL, with smaller cells (<76 fL) described as microcytic and larger cells (>100 fL) as macrocytic (the latter occur in macrocytic anemia).

In microcytic anemia, the red blood cells (erythrocytes) are usually also hypochromic, meaning that the red blood cells appear paler than usual. This is reflected by a lower-than-normal mean corpuscular haemoglobin concentration (MCHC), a measure representing the amount of haemoglobin per unit volume of fluid inside the cell; normally about 320-360 g/L or 32-36 g/dL. Typically, therefore, anemia of this category is described as "microcytic, hypochromic anaemia".

Causes

Typical causes of microcytic anemia include:

• childhood
  • iron deficiency anemia,^[1] by far the most common cause of anemia in general and of microcytic anemia in particular
  • thalassemia
• adulthood
  • blood loss
  • iron deficiency anemia
  • sideroblastic anemia, congenital or acquired
  • anemia of chronic disease,^[2] although this more typically causes normochromic, normocytic anemia. Microcytic anemia has been discussed by Weng et al.^[2]
  • lead poisoning
  • pyridoxine deficiency

Other causes that are typically thought of as causing normocytic anemia or macrocytic anemia must also be considered, and the presence of two or more causes of anemia can distort the typical picture.

See also

• Hypochromic anemia

References

External links

• Emedicine on chronic anemia
• Rare Anemias Foundation