If your kidneys are not working properly, they may not be able to help your body make the red blood cells it needs. Anemia is a common side effect of kidney disease.

What causes anemia?

The two most common causes of anemia in people with kidney disease are:

  • Not having enough iron in your body (called iron deficiency);
  • Not having enough of a hormone called erythropoietin (EPO).

Credit: NIDDK

Your body needs iron and EPO to help your bone marrow make red blood cells. When you breathe, your body keeps the oxygen from the air you inhale. Your red blood cells take that oxygen throughout your body, through your bloodstream, to give you energy and help your organs, bones and muscles work. When you have anemia, there are not enough cells in your blood to carry the oxygen. This can make you feel weak and tired.

Iron is a nutrient that comes from your food. When you don’t have enough iron in your blood, your body cannot make enough red blood cells. Some examples of foods that are high in iron are:

  • Meats
  • Beans
  • Green, leafy vegetables
  • Dried fruits, such as raisins, prunes, and dried apricots.

Your kidneys make the hormone erythropoietin (EPO). EPO tells your bone marrow to make red blood cells. When your kidneys aren’t working well, they cannot make enough EPO. Without enough EPO, your body cannot make enough red blood cells.

What are the symptoms of anemia?

Anemia often does not have any symptoms. If you do have symptoms, they might include:

  • Tiredness
  • Weakness
  • Trouble catching your breath
  • Fast heartbeat
  • Dizziness
  • Headaches
  • Not feeling hungry
  • Trouble sleeping.

How will I know if I have anemia?

The only way to know if you have anemia is to have a blood test. When you have kidney disease, your doctor will want you to have blood tests often. These blood tests are used to check not only your kidney function, but also for signs of any other problems, such as the number of red blood cells and how much iron you have in your body.

The test for anemia is a blood test. It checks for the amount of hemoglobin in your blood. Hemoglobin is a part of your red blood cells. Figuring out the amount of hemoglobin you have in your blood can tell your doctor how many red blood cells you have.

How is anemia treated?

How your anemia is treated depends on what is causing it.

  • Anemia that is caused by having too little EPO can be treated with a type of medicine called an erythropoiesis-stimulating agent (ESA). The ESA tells your bone marrow to make more red blood cells.
  • Anemia that is caused by having too little iron in your body can be treated by taking iron supplements. You can take iron supplement pills or have a shot to add iron directly into your bloodstream. If you are on dialysis, you can also get the iron you need with a medicine that is given through your vascular access, during your dialysis session. This type of iron supplement can also help your ESA medicine work better.

Both types of treatment help your body make more red blood cells. Once you make more red blood cells, you may feel stronger and more awake. If your anemia is not caused by having too little iron or too little EPO, your doctor may choose a different treatment for you. Talk to your doctor about all the treatment options and what treatment is best for you.