Low RBC volume distribution width refers to the condition of low red blood cell volume distribution width.1. Low RBC volume distribution width is caused by the decrease in the number of red blood cells themselves. The most common are the following hematologic diseases, such as aplastic anemia leukemia, myeloma and various chronic hematologic diseases, because the body long-term consumption, the red blood cells will be reduced, which leads to the clinical symptoms and performance of low RBC volume distribution width. 2, in some anemic and blood loss type of disease, there will also be a low distribution width of red blood cell volume. For example, in acute upper gastrointestinal hemorrhage, postpartum hemorrhage, or trauma resulting in hemorrhage, low RBC volume distribution width will also occur.