How Anemia in Chronic Kidney Disease Is Diagnosed

Medically Reviewed by Minesh Khatri, MD on December 18, 2022
2 min read

If you have chronic kidney disease, anemia is a possible complication. But how will your doctor discover if you have anemia?

Doctors usually diagnose anemia based on:

  • Medical history
  • A physical exam
  • Blood tests

To learn your medical history, your doctor may ask about your:

  • Symptoms
  • Past and present health problems
  • Medicines, including over-the-counter meds and supplements
  • Family history

During the physical exam, they might:

  • Take your blood pressure
  • Listen to your heart and lungs
  • Check your skin for rashes, bruising, and other signs of anemia

 

There are several that your doctor can order to figure out if you have anemia. They can include:

Complete blood count. You might have heard of this test called a CBC. It takes just a few minutes and is one of the best ways to check for anemia and other health problems.

A nurse or lab tech takes a small sample of blood from a vein in your arm and sends it to a lab for review. The test shows the number and size of your red blood cells and the amount of hemoglobin they have. Hemoglobin is the protein that carries oxygen throughout your body. 

A CBC may also tell how many new red blood cells you have.

Iron tests. These check how much iron is in your bloodstream. It's done just like a CBC.

Low iron levels are a common cause of anemia in chronic kidney disease. They can happen if there isn't enough iron in the foods you eat, or if your body has a hard time absorbing the iron that your body takes in.

People with chronic kidney disease also lose iron during repeat blood tests and dialysis.  

Nutrient tests. These find out if you have enough to make healthy red blood cells, like vitamin B12 and folate (also called vitamin B9).

Any one of these tests will usually tell your doctor if you have anemia and why you have it. When the cause isn’t clear, you may need to take more than one.

Your doctor usually checks for anemia when you first find out that you have kidney disease. You should have a blood test at least once a year after that. 

Your doctor may test more often if you:

  • Have advanced chronic kidney disease
  • Are on dialysis
  • Take medicine that helps your body make more red blood cells 

You may also need more frequent tests if you

  • Are Black
  • Have diabetes
  • Are over 60 years old

Anemia happens sooner and more often in these groups.

Anemia doesn’t always cause symptoms. It also tends to come on slowly and get worse over time. 

Untreated anemia can make it hard to think clearly or go about your daily tasks. It also makes your heart work harder and can lead to serious heart problems.

Tell your doctor right away if you:

  • Feel tired and weak
  • Have muscle aches
  • Feel chest pain
  • Are short of breath