There are two main causes of anemia in CKD:

CKD and erythropoietin

All of the cells in your body live for a certain amount of time and then die. Your body is always working to make new cells to replace the ones that have died. Red blood cells live for about 115 days. Your kidneys help your body make red blood cells.

Healthy kidneys make a hormone called erythropoietin (EPO). EPO sends a signal to the body to make more red blood cells. If your kidneys are not working as well as they should, they can’t make enough EPO. Without enough EPO, your body doesn’t know to make enough red blood cells. This means fewer red blood cells are available for carrying oxygen through your body.

Healthy kidney:

  • Healthy kidney

  • Normal EPO

  • Normal number of red blood cells

CKD

  • Chronic Kidney Disease

  • Reduced EPO

  • Reduced number of red blood cells

CKD and iron

Iron is a mineral found in many foods, such as meats and leafy greens. Your body uses iron to make red blood cells. A common cause of anemia in people with CKD is iron deficiency. Iron deficiency means you do not have enough iron in your body. It can be caused by not getting enough iron in your diet or by losing blood, either through blood tests or during dialysis. If you don’t take in enough iron through your diet, you can get anemia. Around half of people with CKD stages 2 to 5 have some kind of iron deficiency.

Causes of iron deficiency

  • Not eating enough foods that are rich in iron

  • Iron from your food is not being absorbed properly into your bloodstream

  • Frequent blood donation or testing may increase demand for iron

  • Blood loss from dialysis

Other kinds of anemia

There are several kinds of anemia. Anemia caused by having too little EPO or too little iron in your body are the most common in people with CKD. Talk to your doctor to learn more.