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What is anemia and why am I tired?

To understand anemia, it's important to understand how your blood cells function. Your body contains two types of blood cells: white and red. White blood cells help fight infection, while red blood cells transport oxygen throughout the body. Red blood cells contain a protein called hemoglobin, which combines with the oxygen and releases it to your tissues. When your body is low in red blood cells and hemoglobin, you're said to be anemic. Because of the lack of oxygen in your bloodstream, you may find that you feel very tired.

How does kidney disease contribute to anemia?

There is a link between kidney disease and anemia. Red blood cells are made in your bone marrow. When your kidneys are functioning properly, they release the hormone erythropoietin (EPO), which in turn stimulates the bones to make red blood cells. However, when you have chronic kidney disease, your kidneys may not be able to produce a normal amount of EPO, and anemia results. As your kidney function declines, you may slowly develop anemia and not even be aware of it. This occurs at different times for different people, but once you reach Stage 3 of chronic kidney disease, you are likely to experience some degree of anemia.

The other contributing factor to developing anemia is a lack of iron.

Symptoms of anemia

Some of the symptoms of anemia are as follows:

  • Looking pale or “washed out”
  • Tiring easily
  • Heart palpitations (racing heart)
  • Shortness of breath
  • Hair loss
  • A general sick feeling or sluggishness

How is anemia diagnosed?

A laboratory test called a hematocrit is often used to determine the amount of red blood cells present in your body. The test shows the percentage of volume of the blood that is comprised of red blood cells. For instance, if 50 percent of one ounce of your blood is made up of red blood cells, then you'd be said to have a hematocrit of 50. A normal hematocrit level is in the range of 38 to 47 for women and 42 to 50 for men. Typically, women have lower hematocrit levels because they lose blood regularly due to their menstrual cycles. Also, male hormones stimulate bone marrow to produce red blood cells to a greater degree than female hormones do.

A better indicator of anemia is your hemoglobin level, determined by the number of grams of hemoglobin present in 100 ml of blood. Normal hemoglobin levels for women are in the 12.5 to 15 range. Normal hemoglobin levels for men are in the 14 to 16 range.

If your health care practitioner suspects that your iron levels are low, you may need to be tested. There are two laboratory tests that are used to check your iron level: One is transferrin saturation (TSAT), and the other is ferritin.

Treatment of anemia

Most cases of anemia in people with kidney disease are the result of lack of EPO. Therefore, the most common treatment for anemia is EPO. This protein hormone cannot be administered by mouth so it is given either intravenously (IV) or through injection.

If TSAT and ferritin test results show that you are low in iron, you may need to take iron supplements, either orally or intravenously. Often ferrous sulfate will be prescribed as an oral supplement to help you with iron deficiency.

Many times a person receiving EPO injections will develop iron deficiency and so must begin taking an oral iron supplement. If you receive EPO injections, you should talk to your health care provider about your iron levels.

Although most CKD patients will develop anemia at some point, it can be diagnosed and treated.

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