The common causes of low red blood cells with normal hemoglobin include physiological factors and early stage of anemia. 1. Physiological factors: such as blood dilution caused by various reasons, the blood volume of the circulatory system increases, while the number of red blood cells remains unchanged, the red blood cells per unit volume decreases, therefore, there will be red blood cells low hemoglobin normal. 2. Early stage of anemia: the cause of anemia exists in the body, such as chronic blood loss, etc. In the early stage of anemia, it only manifests as low red blood cells and normal hemoglobin, if the cause of anemia is corrected in time, the red blood cells can be restored to normal, but if the cause of anemia is not dealt with in time, in the long run, there will be a significant decrease in both hemoglobin and red blood cells. Low red blood cells and normal hemoglobin may also have other causes, if the red blood cells and hemoglobin continue to decline, it is recommended to go to the hospital in time, complete the examination to clarify the cause of the disease, and then under the guidance of the physician to give targeted treatment or treatment.