Anemia of Chronic Disease: What to Know
Found in Some People With Long-Term Conditions That Involve Inflammation
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Medically reviewed by Gagandeep Brar, MD
Anemia of chronic disease is a type of anemia caused by inflammation from long-term disorders. Anemia is when you have reduced numbers or function of red blood cells (RBCs), which carry oxygen throughout the body.
Inflammation causes changes in how the body uses iron, which is needed for the oxygen-carrying hemoglobin in red blood cells. The condition results from other long-term health conditions that affect your ability to create red blood cells. It is also known as chronic anemia or anemia of inflammation. About 1 million Americans over age 65 have anemia of inflammation.
This article will define anemia of chronic disease, including what it is, what type of anemia it is, and common causes, symptoms, features, levels, and characteristics.
It will discuss the testing and lab values required for a diagnosis of chronic anemia and what happens as the disease progresses, as well as the difference between iron-deficiency anemia and anemia of chronic disease.
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What Is Anemia of Chronic Disease?
Anemia is a lack of healthy red blood cells with enough protein called hemoglobin. Hemoglobin requires iron to bring oxygen from the lungs to organs and tissues throughout the body.
If the body has too few red blood cells, if these cells are not fully formed and healthy, or if they don’t have enough hemoglobin or iron, they won’t be able to transport enough oxygen. Without enough oxygen, the body parts can’t function correctly. This is called anemia.
There are many different types of anemia. Anemia of chronic disease is one of the more common types. The most common type of anemia is iron-deficiency anemia, but this has different characteristics, causes, and treatments from anemia of chronic disease.
Anemia of chronic disease is anemia caused by inflammation from a long-term or chronic illness. It is also called anemia of inflammation.
People with anemia of chronic disease may have normal or even high levels of iron in the body’s tissues. But they have low iron in the blood and not enough healthy red blood cells.
Underlying Conditions That Cause Chronic Anemia
Several long-term conditions can cause anemia of chronic disease. For instance, anemia of chronic disease can develop in people with cancers, especially blood cancers like lymphoma, including Hodgkin's disease.
Anemia of chronic disease is also common in people with varying types of autoimmune conditions. These can include:
People with chronic infections can develop anemia of inflammation. These include:
Tuberculosis
Human immunodeficiency virus (HIV)
Hepatitis B or C
Infection of the heart lining (bacterial endocarditis)
Bone infections (osteomyelitis)
Lung abscess
People with chronic kidney disease, diabetes, and heart failure are also at a high risk of developing anemia of inflammation.
Risk Factors for Anemia of Chronic Disease
The biggest risk factor for developing anemia of chronic disease is having a long-term illness that causes inflammation. It is more likely to develop as a person ages since older people are more likely to have a chronic disease.
When dealing with chronically high levels of inflammation, your body changes in ways that may lead to anemia. These include:
The body changes the ways it stores and uses iron.
The kidneys may make less of the hormone erythropoietin (EPO) that tells the bone marrow to make red blood cells.
The bone marrow stops responding to EPO.
The red blood cells that the bone marrow makes are more fragile. They die faster than usual and faster than they can be replaced.
Other Causes of Chronic Anemia
Aside from inflammation, other symptoms and bodily changes caused by the chronic illness can also work to cause or worsen anemia.
For example, in chronic kidney disease, EPO levels may be low not only because of inflammation but because the kidneys struggle to produce enough of the hormone due to kidney damage. A person with a restricted diet due to chronic kidney disease may not get enough nutrients to make red blood cells. Losing blood due to hemodialysis can also lead to iron-deficiency anemia.
Blood loss is also likely a factor in anemia brought on by chronic digestive conditions like inflammatory bowel disease (IBD). IBD includes ulcerative colitis and Crohn's disease), which may cause both iron-deficiency anemia due to blood loss and anemia of chronic disease.
Anemia due to cancer is often a mix of blood loss, side effects from treatments such as chemotherapy and radiation, and due to cancers that affect or spread to the bone marrow, where red blood cells are made.
It is also possible for older adults to develop anemia of inflammation without having a chronic disease or infection.
Symptoms of Anemia of Chronic Disease
Early in its course, anemia of inflammation may not have symptoms. It develops slowly. As it progresses, anemia can have mild to severe symptoms. Symptoms of anemia of chronic disease include:
Feeling weak or tired, especially during physical activity
Headache
Looking pale
Being short of breath
Speedy heartbeat
Body aches
Being dizzy or light-headed
What Tests Diagnose Chronic Anemia?
A healthcare provider will examine you to check for anemia and ask about your symptoms and your chronic disease. They'll run many blood tests to see if your chronic condition is causing anemia. Tests and related lab values that indicate anemia of chronic disease include the following.
Laboratory normal ranges used to diagnose anemia vary by the sex assigned at birth. (Note that in this article, the terms for sex or gender from the sources cited are used.)
A complete blood count (CBC), peripheral smear, and reticulocyte count to study the blood cells include these indications of anemia:
RBC count: The number of red blood cells in your blood should be 4.7 to 6.1 million cells per microliter (mcL) for adult males and 4.2 to 5.4 million cells/mcL for adult females. Lower numbers indicate anemia.
Hemoglobin: Hemoglobin under 13.8 grams per deciliter (g/dL) for adult males or 12.1 g/dL for adult females would indicate anemia.
RBC indices and appearance: The CBC and peripheral smear also examine the red blood cells' size, shape, and color, which can provide clues to the type or cause of anemia.
Reticulocyte count: The reticulocyte count is the number of developing red blood cells. A normal result for healthy adults not anemic is 0.5% to 2.5%.
Blood tests to check iron levels include:
Serum iron: The normal range for this is 40 to 165 micrograms per liter (μg/L). Levels below this indicate anemia.
Serum transferrin: Transferrin is a protein in your blood that carries iron into the cells. Normal serum transferrin level is between 200 and 400 milligrams per deciliter (mg/dL).
Transferrin saturation: Transferrin levels are used to calculate transferrin saturation, which tells the healthcare provider how much iron is available to your body. A transferrin saturation below 20% indicates anemia.
Serum ferritin: Ferritin is a protein that stores iron in your body's cells. If ferritin falls below 100 μg/L in a person with a chronic condition, that would indicate that your body doesn't have enough iron.
Other tests include:
C-reactive protein level between 1.0 to 10.0 mg/dL or higher indicates that the body is experiencing systemic inflammation, often caused by chronic diseases.
The erythrocyte sedimentation rate (ESR), or sed rate, is a measurement that indicates how much inflammation is in the body. For adults over 50, ESR should be less than 20 millimeters per hour (mm/hr) in men and less than 30 mm/hr in women.
Rarely a bone marrow biopsy is performed to rule out cancer.
Treatment for Anemia of Chronic Disease
Anemia is often mild enough that it does not need treatment. The first line of treatment for anemia of chronic disease is treating the condition causing the inflammation or working to reduce the inflammation caused by the disease. Treatment may improve or cure anemia.
Procedures that might be needed include:
Blood transfusions can quickly increase the hemoglobin in your blood and boost oxygen. This is a short-term fix.
Intravenous medicines and iron supplements given during hemodialysis can reduce and prevent anemia in people with chronic kidney disease.
Medicines:
EPO itself can be given as a shot.
Shots of erythropoiesis-stimulating agents (ESAs), epoetin alpha or darbepoetin alpha, can trigger the bone marrow to make more red blood cells.
Depending on the characteristics of your illness (but not in all cases), your healthcare provider may suggest Iron supplements as pills or shots.
Anemia of Chronic Disease vs. Iron-Deficiency Anemia
Anemia of chronic disease is different from iron-deficiency anemia.
In iron-deficiency anemia, the body doesn’t have enough stored iron to make enough healthy red blood cells. Iron levels are low in both body tissues and the blood.
In anemia of chronic disease, the body has iron stores in the body tissues, but the body can’t use it to make enough healthy red blood cells. Typically, iron levels are high in the body but low in the blood.
The symptoms of the two are similar, but the causes are different. In some cases, such as diseases that result in blood loss, people can have both types of anemia.
Possible Complications of Anemia of Chronic Disease
Most of the time, the symptoms of anemia are the most significant complication. Anemia of chronic disease can increase the risk of death in people with heart failure. In people with chronic kidney disease, severe anemia can lead to heart problems. And untreated, severe anemia can be life-threatening.
Does Anemia of Chronic Disease Get Better?
Generally, the outlook for people with anemia of chronic disease is promising. Most people improve when the anemia cause is discovered and treated.
Dietary and Lifestyle Changes for Chronic Anemia
A healthy diet is recommended. Your healthcare provider can share information on what you should be eating and refer you to a dietitian for nutritional counseling.
Depending on the underlying condition and how it affects nutrient absorption and use, a healthcare provider may recommend changes to address specific nutrient deficiencies, like iron, folic acid, or vitamin B12.
When to Contact a Healthcare Provider
If you have a long-term disorder or chronic disease and start showing anemia symptoms, let your healthcare provider know. They’ll do an exam and blood tests to diagnose anemia and work with you to treat the cause. Treatment helps most people with anemia of chronic disease feel better.
Summary
Anemia of chronic disease is a common type of anemia. Inflammation from long-term or chronic diseases causes it. It is also known as anemia of inflammation.
Cancer, autoimmune conditions, chronic infections, and other conditions can all cause anemia of chronic disease. Symptoms may include weakness, fatigue, headache, pale appearance, and shortness of breath.
Blood tests for anemia include a complete blood count and iron and iron-related protein levels. Treatment involves addressing the underlying chronic disease or reducing inflammation.
Blood transfusions, EPO, and medicines to stimulate red blood cells can treat anemia. Supplemental iron may or may not be recommended, as this type of anemia differs from iron-deficiency anemia, but they can occur together. With treatment, the outlook for people with anemia of chronic disease is generally favorable.
