A low mean red blood cell volume represents a small red blood cell volume and is seen in simple microcytic anemia or microcytic hypochromic anemia. The Mean Red Blood Cell Volume looks at the morphology of the red blood cells, which in turn helps to diagnose the disease. It is calculated by dividing the hematocrit by the number of red blood cells per liter of blood. The reference range is 80-100fl, below 80fl is considered low. Simple microcytic anemia can be seen in various chronic infections, chronic inflammation, liver disease, uremia and other causes of anemia, but also in malignant tumors, rheumatic diseases caused by anemia, this kind of anemia, the average volume of red blood cells are on the low side, but the average concentration of red blood cell hemoglobin is normal. Microcytic hypochromic anemia, which can be seen in iron-deficiency anemia, iron granulocytic anemia, and also in bead protein production disorder anemia, the average volume of red blood cells and the average erythrocyte hemoglobin concentration are low. Low mean red blood cell volume can be seen in a variety of anemia, it is recommended to consult a doctor for a clear diagnosis and timely treatment.