Chemotherapy-induced anemia (CIA) occurs when a person develops anemia as a side effect of chemotherapy. Symptoms can include fatigue, dizziness, and increased heart rate.

Chemotherapy is a type of drug treatment for many types of cancer. The aim of chemotherapy is to stop the spread and multiplication of rapidly dividing cancer tumor cells.

However, the chemicals in chemotherapy drugs may also damage other cells that are rapidly dividing. This can cause side effects such as CIA.

Anemia occurs when a person’s body does not produce enough healthy red blood cells or hemoglobin to transport oxygen to the cells throughout the body.

This article looks at what causes CIA, the symptoms of CIA, and how doctors may diagnose it. It also discusses available treatment options for the condition and the possible complications.

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Some chemicals in chemotherapy drugs inhibit erythropoiesis, which is the process by which the body produces new red blood cells.

Additionally, chemotherapy targets other rapidly dividing cells, such as the erythroid progenitor cells. These are the stem cells that give rise to erythrocytes, or red blood cells. Chemotherapy drugs may stimulate eryptosis, a type of cell death in red blood cells.

These two effects can lead to CIA.

Learn more about chemotherapy.

Symptoms of CIA include:

However, these symptoms may also be due to other health conditions. If a person is experiencing possible symptoms of anemia, it is best to contact a doctor for a diagnosis.

Learn more about anemia.

To diagnose CIA, a doctor may begin by:

  • performing a physical examination
  • asking questions about symptoms
  • taking a full medical history, including information on chemotherapy and any other treatments the person is currently receiving

The doctor may then order various tests to confirm the presence of anemia and rule out other possible causes.

One such test is a complete blood count, which provides information about various components of the blood, including:

  • Red blood cell levels: Red blood cell levels that are higher or lower than usual may indicate anemia.
  • Hemoglobin levels: Hemoglobin is the protein in red blood cells that carries oxygen. Lower levels may also indicate anemia.
  • Hematocrit levels: Hematocrit is a measure of the amount of space red blood cells take up in the blood. Hematocrit levels that are too low may indicate anemia.
  • Mean corpuscular volume (MCV) levels: MCV is a measure of the average size of the red blood cells themselves. Levels that are too low might suggest a possible cause of anemia.

Learn more about complete blood counts.

A doctor may order a bone marrow test to see whether the bone marrow is healthy and makes a typical amount of blood cells. The bone marrow is the fatty tissue within bones, and it produces blood cells and platelets.

This test may involve either an aspiration or a biopsy. During an aspiration, a doctor collects a small amount of bone marrow fluid using a needle. A biopsy involves collecting a small amount of bone marrow tissue using a larger needle.

The doctor can discuss with a person the tests they order and answer any questions.

The aim of treatment for CIA is to restore the typical amount of red blood cells in the body and allow for the efficient transport of oxygen to cells throughout the body.

Blood transfusion

One treatment option is a red blood cell transfusion from a donor. The donor blood will need to match the recipient’s blood type to prevent the recipient’s immune system from rejecting the blood.

Blood transfusions may benefit a person experiencing severe and symptomatic anemia or bleeding.

A doctor will consider several factors before administering a blood transfusion, including:

  • the intensity and nature of a person’s ongoing chemotherapy treatment
  • other health conditions a person may have
  • the speed of hemoglobin decline

Learn more about blood transfusions and anemia.


Doctors may recommend medications that stimulate the production of red blood cells for CIA.

Erythropoietin-stimulating agents (ESAs) are recombinant versions of erythropoietin (EPO), the hormone in the body that stimulates red blood cell production. ESAs stimulate the division and differentiation of erythroid progenitor cells.

Examples of ESAs include:

  • epoetin
  • darbepoetin
  • methoxy polyethylene glycol-epoetin beta

A 2020 review notes that it is best to avoid ESAs when the goal of treatment is to cure the cancer. This is because they increase the risk of thromboembolic events in people with CIA.

The review authors note that it may take 4–6 weeks for a person with CIA to experience a positive effect from ESA treatment. They also state that one-third of people with CIA do not respond to ESA alone.

The duration of CIA may vary depending on the type of chemotherapy drugs a person is taking, the dosage of those drugs, and the person’s overall health.

According to the Canadian Cancer Society, a person with CIA may notice an improvement in their symptoms 2–4 weeks after completing chemotherapy.

Anemia has the potential to affect a person’s quality of life and may shorten survival time in people with cancer.

Because the cells are not receiving enough oxygen, a person may feel more tired and their heart may have to work harder. This may lead to heart problems or worsen existing heart conditions.

Severe anemia may also affect or delay cancer treatment, and a doctor may have to reduce the chemotherapy dose. As a result, the cancer treatment may be less effective.

A person’s doctor can advise them on how to manage anemia and reduce the risk of complications.

Chemotherapy-induced anemia (CIA) is a side effect of chemotherapy that can occur when chemotherapy drugs damage cells in the bone marrow that produce red blood cells.

Symptoms of CIA include fatigue, shortness of breath, and dizziness.

Doctors can diagnose CIA after a physical exam, blood tests, and a bone marrow aspiration or biopsy. Treatment for CIA may include blood transfusions and medications that stimulate red blood cell production.

The duration of CIA will depend on the type of chemotherapy drugs, the dosage, and the person’s overall health. A person’s doctor can provide more information about how to manage anemia and what to expect.