Microcytosis or microcythemia is a condition in which

red blood cells Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek language, Greek ''erythros'' for "red" and ''k ...

are unusually small as measured by their

mean corpuscular volume The mean corpuscular volume, or mean cell volume (MCV), is a measure of the average volume of a red blood corpuscle (or red blood cell). The measure is obtained by multiplying a volume of blood by the proportion of blood that is cellular (the hema ...

. When associated with

anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, th ...

, it is known as

microcytic anemia Microcytic anaemia is any of several types of anemia characterized by smaller than normal red blood cells (called microcytes). The normal mean corpuscular volume (abbreviated to MCV on full blood count results, and also known as mean cell volume) ...

Causes

Microcytic anemia is not caused by reduced DNA synthesis.

Thalassemia Thalassemias are inherited blood disorders characterized by decreased hemoglobin production. Symptoms depend on the type and can vary from none to severe. Often there is mild to severe anemia (low red blood cells or hemoglobin). Anemia can result ...

can cause microcytosis. Depending upon how the terms are being defined, thalassemia can be considered a cause of microcytic anemia, or it can be considered a cause of microcytosis but not a cause of microcytic anemia. There are many causes of microcytosis, which is essentially only a descriptor. Cells can be small because of mutations in the formation of blood cells (hereditary microcytosis) or because they are not filled with enough hemoglobin, as in iron-deficiency-associated microcytosis. Red blood cells can be characterised by their haemoglobin content as well as by their size. The haemoglobin content is referred to as the cell's colour. Therefore, there are both "normochromic microcytotic red cells" and "hypochromic, microcytotic red cells". The normochromic cells have a normal concentration of haemoglobin, and are therefore 'red enough' while the hypochromic cells do not; thus the value of the

mean corpuscular hemoglobin concentration The mean corpuscular hemoglobin concentration (MCHC) is a measure of the concentration of hemoglobin in a given volume of packed red blood cell. It is calculated by dividing the hemoglobin by the hematocrit. Reference ranges for blood tests are 3 ...

.The most common cause of microcytosis is iron deficiency anemia. Every time Hb synthesis being impaired in bone marrow microcytosis can occurs such as iron deficiency and Hb pathy may occur in fact when Hb production was impaired: size of each RBCs is decreased in early stage to save mean corpuscular Hb concentration : i.e. MCHC: so MCV is decreased as compensating mechanism.

References

External links

Red blood cell disorders Clinical pathology Abnormal clinical and laboratory findings for RBCs {{pathology-stub de:Mikrozytose

Causes

See also

References

External links