Anemia of Chronic Disease: Understanding Your Pathology Report

Anemia of chronic disease (ACD) is a type of anemia that develops in people with long-standing illnesses that cause inflammation. Anemia means that the blood has fewer red blood cells than normal or that the red blood cells contain less hemoglobin.

Red blood cells are the cells in the blood that carry oxygen from the lungs to the rest of the body and return carbon dioxide to the lungs to be exhaled. They carry oxygen using a protein called hemoglobin. When there are not enough healthy red blood cells or hemoglobin, the body cannot get enough oxygen, which leads to the symptoms of anemia.

What causes anemia of chronic disease?

ACD is caused by long-term medical conditions that interfere with the way the body makes and uses red blood cells.

Common conditions that can cause ACD include:

• Chronic infections, such as HIV or tuberculosis.

• Kidney disease, where the kidneys cannot make enough of a hormone called erythropoietin (EPO). EPO normally signals the bone marrow to make new red blood cells.

• Cancer, which can cause inflammation and suppress bone marrow function.

• Autoimmune diseases, such as rheumatoid arthritis or lupus, where the immune system causes long-term inflammation.

Chronic inflammation reduces the amount of iron absorbed from food and prevents the body from using stored iron effectively. It also lowers the amount of EPO made by the kidneys and decreases how well the bone marrow responds to EPO. Together, these changes result in fewer new red blood cells being made.

What are the symptoms of anemia of chronic disease?

Some people with ACD have no noticeable symptoms, and the anemia is discovered only after routine blood tests. When symptoms do occur, they are usually related to the reduced ability of the blood to carry oxygen.

These symptoms may include:

• Fatigue and weakness.

• Shortness of breath, especially with exertion.

• Dizziness or lightheadedness.

• Chest pain or palpitations (a feeling that the heart is racing).

The severity of symptoms depends on how low the hemoglobin levels are and whether other medical conditions are also present.

How is this diagnosis made?

The diagnosis of ACD is made through a combination of blood tests and by reviewing the person’s medical history.

• Complete blood count (CBC): This test measures the number and size of red blood cells. In ACD, red blood cells are often normal in size (normocytic), but in some cases, they may be smaller than normal (microcytic).

• Iron studies: These tests measure the amount of iron stored in the body and how it is used. In ACD, the ferritin level (a measure of stored iron) is usually normal or high, even though the body cannot use the iron effectively. This pattern is different from iron deficiency anemia, where ferritin levels are low.

• Additional testing: Doctors may also perform tests to rule out other causes of anemia, such as vitamin B12 or folate deficiency.

Because ACD often occurs alongside other conditions, doctors will also consider the underlying disease and whether more than one type of anemia is present.

Why is anemia of chronic disease important?

ACD itself is usually not life-threatening, but it can significantly affect quality of life by causing fatigue and reduced physical capacity. More importantly, ACD often reflects the activity of another chronic illness, such as kidney disease, cancer, or autoimmune disease. Treating the underlying condition often improves the anemia.

Questions to ask your doctor

If you have been diagnosed with anemia of chronic disease, you may wish to ask your doctor the following questions:

• What is causing my anemia?

• Do I also have iron deficiency anemia or another type of anemia?

• How severe is my anemia, and what does it mean for my overall health?

• Will treating my underlying condition improve my anemia?

• Are there treatments available to increase my red blood cell count, such as iron supplements or erythropoietin therapy?