Anemia in People With Cancer

What is anemia?

When you don’t have enough healthy red blood cells, you have a condition called anemia. This means your blood has too little hemoglobin (Hgb), the part of the red blood cell (RBC) that carries oxygen to all the cells in your body.

Anemia often starts slowly, so you may not even notice symptoms at first. As your hemoglobin level gets lower you may have one or more of these symptoms:

  • Fast heart beat
  • Shortness of breath
  • Trouble breathing when doing things like walking, climbing stairs, or even talking
  • Dizziness
  • Chest pain
  • Swelling in the hands and/or feet
  • Pale skin, nail beds, mouth, and gums
  • Extreme tiredness (fatigue)

Severe tiredness and weakness are often the symptoms that bother people most.

What causes anemia?

There are many different reasons a person with cancer might have anemia. Some common causes are:

  • The cancer itself
  • Cancer treatment, such as radiation or chemotherapy
  • Blood loss (this can be slow constant bleeding such as from the intestine or bladder; or fast bleeding, like heavy menstruation or bleeding from a stomach ulcer)
  • Missing certain vitamins or minerals in the diet
  • Low iron levels in blood
  • Major organ problems (including severe heart, lung, kidney, or liver disease)
  • Red blood cells (RBCs) being destroyed by the body before they’re replaced
  • Chronic kidney disease
  • The body making fewer RBCs
  • Sickle cell disease or thalassemia (inherited disorders that cause the body to destroy too many red blood cells)
  • A combination of any of these factors

Some risk factors may make a person with cancer more likely to have anemia. These include:

  • Platinum-based chemotherapy (this is a certain group of chemo drugs)
  • Certain tumor types (such as lung or ovary tumors)
  • Having a low hemoglobin level before you had cancer

Tests for what is causing your anemia

A complete blood count (CBC) is a blood test that measures your hemoglobin level and other characteristics of your red blood cells (such as their size). This test not only shows if you have anemia, but it can also help your doctor figure out what might be causing it.

You might also need other tests to help to find what is causing it. These could include:

  • Blood chemistry tests to check organ function and levels of vitamins and minerals
  • A blood test called a reticulocyte count (Reticulocytes are very young red blood cells just released from the bone marrow, so this test shows how many new red cells your body is making.)
  • A bone marrow exam
  • A blood test to look at your iron levels
  • A test of your stool (feces) to check for blood (called a fecal occult blood test or FOBT)

Your doctor or nurse can use the results of these tests, along with your medical information and a physical exam, to get an idea of what might be causing your anemia. Sometimes no cause can be found other than “anemia of chronic disease.” This type of anemia is often found in people with long-lasting problems like congestive heart failure, inflammatory diseases, or cancer.

What problems can anemia cause?

Learning the cause of the anemia is important, but the first thing the doctor needs to know is how “bad” it is.

Anemia can affect your quality of life and has been found to shorten survival in people with cancer. It can make you feel very tired because cells in your body can’t get enough oxygen. In some cases, this lack of oxygen may be bad enough to threaten your life. Anemia can also make your heart work harder. So if you already have a heart problem, anemia can make it worse.

Severe anemia may mean you have to delay your cancer treatment or have your treatment dose reduced. It can also cause some treatments to not work as well as they should.

Your doctor or nurse may try to figure out your risk of serious problems from the anemia based on any symptoms you are having and your hemoglobin level. If you’re not having symptoms, they will try to figure out how likely you are to have them in the near future. This will be based on a number of things, including:

  • Your hemoglobin level and other lab results
  • The type of cancer treatments you’ve had in the past
  • The chances that any treatments you’re now getting could make the anemia worse
  • Your need for blood transfusions in the past 6 months
  • Whether you have lung, heart, or blood vessel (circulation) problems
  • Your age

If you don’t seem to be at risk for problems from anemia, your doctor or nurse will watch your hemoglobin level closely and ask about symptoms each time you visit the office.

How bad is the anemia?

Doctors often rate how severe or how “bad” anemia is based on the amount of hemoglobin in your blood. Even though your symptoms may not match, doctors use this way to rank anemia when deciding about treatment.

    Mild anemia: hemoglobin between 10 and the lower limit of normal for your age, sex, and the lab value
    Moderate anemia:
    hemoglobin 8 to 10 g/dL
    Severe anemia:
    hemoglobin 6.5 to 8 g/dL
    Life-threatening anemia:
    hemoglobin less than 6.5

Some serious symptoms of anemia are:

  • Chest pain
  • Fast heart beat
  • Swelling in your legs
  • Feeling dizzy or lightheaded
  • Having trouble breathing when you exert yourself

If you have any of these symptoms, tell your doctor or nurse right away.

Other medical problems such as heart disease or chronic lung disease may already affect how much oxygen is getting to your body. These conditions along with anemia could increase your risk of serious problems. If your cancer care team finds that your anemia is a serious threat to your health, you may need a blood transfusion.

How is anemia treated?

There are 2 main goals in treating anemia:

  • Treat the cause of the anemia
  • Raise the hemoglobin level so that symptoms get better

Depending on the cause of the anemia, treating it may include things like eating iron-rich foods, medicines, delaying or changing cancer treatment; and stopping any bleeding.

If the hemoglobin level needs to be raised quickly, a transfusion of red blood cells may be given.

Talk to your cancer care team about what treatment is right for you. As with any medical problem, the expected benefits of treatment should always outweigh the possible risks.

Iron-rich foods for anemia

If your anemia is mild, you may be asked to try to eat more iron-rich foods. Foods that contain high amounts of iron include

  • Dark green
  • Leafy vegetables
  • Sweet potatoes
  • Prunes and raisins
  • Dried apricots and peaches
  • Beans
  • Meat and fish
  • Enriched bread, cereal, and pasta

Ask your healthcare provider which foods would be best for you.

The American Red Cross has a detailed list of iron-rich foods on their website,

Blood transfusions to treat anemia

A red blood cell transfusion is safe, and a common way to treat anemia in people with cancer. It raises the level of hemoglobin quickly to improve symptoms, help the patient feel better, and make sure that enough oxygen is getting to vital organs.

The need for a blood transfusion depends on how bad your symptoms are and your hemoglobin level. A transfusion is done most often when the hemoglobin level is less than 8 g/dL.

A blood transfusion requires careful matching of donated blood to the recipient’s blood. And while blood transfusions fix the problem very quickly, there is a small chance of serious risks. The most common problem is a transfusion reaction. This happens when the patient’s immune system attacks proteins on the foreign blood cells. This often looks like an allergic reaction. Most of these reactions are minor and can be treated, but sometimes they can be more serious.

Transfusion-related lung injury is one of the more serious risks. It can cause trouble breathing and require treatment in the hospital. Another possible risk is the chance of getting certain germs, such as the hepatitis B virus. But the careful blood testing and screening that’s used today have made the risk of infections very small.

In some people, transfusion-related circulatory overload (TACO) can happen if blood is given too quickly for the heart to handle it. And people who get many blood transfusions (usually more than 25 units of red cells) may end up with too much iron, which would then need to be treated.

Contact us at 1-800-227-2345 or explore to learn more about blood transfusions.

Drugs to treat anemia

Many different drugs can be used to treat anemia, but this takes longer. In some cases, taking iron, vitamin B12, and/or folic acid supplements can help. There’s also a liquid form of iron that can be put right into your blood (as an IV infusion).

Another way to treat anemia in some patients is to use drugs that tell the body to make more red blood cells. These drugs work like a hormone (called erythropoietin) made by the kidneys to help the body make its own new red blood cells. If one of these drugs is recommended, your healthcare provider will talk to you about the risks and the benefits of the drug. These drugs can cause very serious side effects. Still, they can help patients getting chemotherapy have higher hemoglobin levels and need fewer blood transfusions. This may result in a gradual improvement of anemia-related symptoms.

These drugs are given as shots under the skin, and usually take at least 2 weeks to start working.

If you notice symptoms…

It’s important to watch for anemia and its symptoms throughout your treatment. Tell your cancer care team if you’re having any of the symptoms described here. Be sure to mention how the symptoms affect your day-to-day life. Doing so will help you get the treatment you need when you need it.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

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National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology. Cancer- and Chemotherapy-Induced Anemia – V.2.2016. Accessed at on April 7, 2016.

National Heart, Lung, and Blood Institute. Explore Anemia. Accessed at on April 7, 2016

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Last Medical Review: April 11, 2016 Last Revised: February 13, 2017

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