Anemia caused by kidney disease is called renal anemia. There are many reasons for the formation of renal anemia: 1. Reduced erythropoietin production: This is the most important reason for the formation of renal anemia. Erythropoietin is mainly produced in the distal tubules of the kidney, renal cortex and outer medullary capillary endothelial cells, etc. With the development of renal diseases and the destruction of renal tissues, erythropoietin is constantly reduced, leading to anemia. 2, red blood cell life shortened: under normal circumstances, the life of human red blood cells is about 120 days, while the life of red blood cells in uremic patients is only about 25 days, significantly shorter than normal people, why is this? There are studies: the normal person’s red blood cells into uremic patients, the input red blood cell life significantly shortened, the uremic patient’s red blood cells into normal people, the input red blood cell life is close to normal, indicating that the presence of toxic substances in the body of uremic patients to shorten the life of red blood cells. 3, erythropoiesis inhibitory factor: uremic patients have substances in the plasma that inhibit erythropoiesis, and the substances that are known are mainly some medium-molecule substances, such as parathyroid hormone, arginine and polyamines arginine, etc. 4. Deficiency of hematopoietic substances: Chronic kidney disease leads to reduced absorption or loss of vitamin B12, folic acid and iron in patients, mainly due to decreased gastrointestinal function and decreased appetite. Hemorrhage and hemodialysis can also lead to iron loss. 5, chronic blood loss: chronic kidney patients often bleed, mainly due to bleeding gums, gastrointestinal bleeding, excessive menstruation, etc. leading to blood loss. In addition, hemodialysis and excessive check-ups can also cause blood loss and aggravate anemia. From the above analysis tells us that the treatment of renal anemia needs systematic and comprehensive measures to improve gradually.