What is anemia?

If your red blood cell count is low, you might have a condition called anemia (uh-nee-me-uh). The red blood cell count is measured with a blood test called a CBC. (CBC stands for complete blood count.) Anemia means your blood has too little hemoglobin (he-muh-glo-bin). Hemoglobin is the part of the red blood cell (RBC) that carries the oxygen your body uses.

Doctors often define anemia as a hemoglobin (Hb) level of less than 12 g/dL (grams per deciliter). But many people do not feel much different until the hemoglobin level falls below 11 g/dL. Symptoms of anemia often happen slowly, so you may not even notice them at first. But the symptoms get worse as the hemoglobin gets lower. These symptoms can include:

• a 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)

Fatigue, or severe tiredness and weakness, is often the symptom that bothers people most. All of these symptoms are signs that your body tissues aren't getting enough oxygen. For more information on fatigue see our document Fatigue in People with Cancer.

What causes anemia?

There are many different causes of anemia in people with cancer. Some of them may have nothing to do with your cancer. The more common causes of anemia in people with cancer 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 excess menstrual bleeding, or bleeding from a stomach ulcer)
• certain vitamins or minerals missing in a person's diet
• major organ problems (including severe heart, lung, kidney, or liver disease)
• red blood cells (RBCs) being destroyed by the body before they're replaced
• the body making fewer RBCs
• sickle cell disease or thalassemia (inherited disorders)
• a combination of these factors

There are some risk factors that may make you more likely to have anemia. These include:

• getting platinum-based chemotherapy
• certain tumor types (such as lung or ovary tumors)
• having a low hemoglobin level before you had cancer

Tests to look for the cause of anemia

If you have a hemoglobin level lower than 11 g/dL your doctor will ask questions about your past and current medical conditions and do a physical exam. Other tests may be needed to help to find the cause of your anemia. These could include the following:

• blood chemistry tests to check organ function, and levels of vitamins and minerals
• a reticulocyte count (this test looks at the number of red cells your body is making -- reticulocytes are the young red cells just released from the bone marrow)
• a bone marrow exam
• iron studies
• a test to check for blood in your stool (feces) 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 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?

Finding out what is causing the anemia is important. But it's even more important to figure out how severe or how bad it is. Anemia causes fatigue when cells in the body are not able to get enough oxygen. In some cases, this may be severe enough to become life threatening. Anemia can also cause your heart to 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 are not having symptoms, the doctor 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 have had in the past
• the chances that any treatments you are now getting could make your anemia worse
• your need for blood transfusions in the past 6 months
• whether you have lung or heart problems
• your age

If you do not seem to be at risk for anemia, your doctor or nurse will watch your hemoglobin level closely and ask about your symptoms each time you return to the office.

How bad is the anemia?

Even though your symptoms may not match this ranking of lab results, doctors often rate how severe the anemia is as part of deciding about treatment.

Chest pain, fast heart beat, swelling in your legs, feeling lightheaded, or having trouble breathing when you exert yourself are serious symptoms of anemia. 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 health care team finds that your anemia is a serious threat to your health, you may need a blood transfusion. (See the next section.)

Treating anemia

There 2 main goals in treating anemia:

• to treat the cause of the anemia
• raise the hemoglobin level so that the symptoms will go away

Depending on the cause of the anemia, treating it may include things like eating nutrient-rich foods, taking iron and folic acid supplements, and stopping any bleeding.

In cases where the hemoglobin level needs to be raised quickly, a transfusion of red blood cells may be given. Some cancer patients whose treatment has caused anemia may be able to use certain drugs to raise their hemoglobin levels, although this takes longer. See the later section "Drugs to treat anemia." Talk to your doctor about what treatment is right for you. As with any medical problem, the expected benefits of treatment should always outweigh the possible risks.

Blood transfusions to treat anemia

Red blood cell transfusions are a common way to treat anemia. 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. This raises the level of hemoglobin quickly to make the patient feel better and make sure that enough oxygen is getting to vital organs.

Blood transfusions fix the problem very quickly, but they do carry a small chance of serious risks. The most common problem is a transfusion reaction. This happens when a patient's immune system attacks proteins on the foreign blood cells. Most of these reactions are minor and can be treated, but sometimes they can be more serious. These often look like allergic reactions. 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 screening that is used today has made the risk of infections very small. In some people, congestive heart failure 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 need to be treated. For more detail on transfusions, see our document Blood Product Donation and Transfusion.

Drugs to treat anemia

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 erythropoeitin (e-rith-ro-PO-eh-tin), a hormone that is made by the kidneys to help the body make its own new red blood cells. The drugs are epoetin (e-PO-eh-tin), also called Epogen^® or Procrit^®, and darbepoetin (dar-beh-PO-eh-tin) which is also called Aranesp^®. These drugs are given as shots (injections) under the skin. They can relieve symptoms of anemia and reduce the need for blood transfusions, but it usually takes at least 2 weeks for them to start working.

These anemia drugs are only used in patients who are getting chemotherapy that is not expected to cure their cancer. Some studies have shown that these drugs can cause serious or life-threatening side effects such as high blood pressure and blood clots. Newer studies suggest that they may cause cancer growth and shorten life in some people. These drugs should only be used for patients being actively treated for cancer, and their risks and benefits should be taken into account.

Still, studies have shown that the using these drugs in patients getting chemotherapy can raise their hemoglobin levels and lessen their need for blood transfusions. Please call us if you would like more information about these or other drugs used in cancer treatment.

So…

It is important to watch for anemia and its symptoms carefully throughout your treatment. Talk with your doctor or cancer team if you are having these symptoms. Be sure to mention how the symptoms affect your day to day life. Doing so will help you and your doctor or nurse know that you are getting the treatment you need when you need it.

Additional resources

More information from your American Cancer Society

We have selected some related information that may also be helpful to you. These materials are on our Web site or can ordered from our toll-free number.

• Fatigue in People With Cancer

• Blood Product Donation and Transfusion

• Caring for the Cancer Patient at Home: A Guide for Patients and Families

• Nutrition for the Person with Cancer During Treatment: A Guide for Patients and Families (also available in Spanish)

• Physical Activity and the Cancer Patient

• Nutrition and Physical Activity During and After Cancer Treatment: Answers to Common Questions

• Understanding Chemotherapy: A Guide for Patients and Families (also available in Spanish)

• Understanding Radiation Therapy: A Guide for Patients and Families (also available in Spanish)

• A Message of Hope: Coping with Cancer in Everyday Life (also available in Spanish)

• After Diagnosis: A Guide for Patients and Families (also available in Spanish)

The following books are available from the American Cancer Society. Call us to ask about costs or to place your order.

• What Helped Get Me Through: Cancer Survivors Share Wisdom and Hope

• Cancer in the Family (for parents with cancer)

• Couples Confronting Cancer

• What to Eat During Cancer Treatment

• Caregiving: A Step-By-Step Resource for Caring for the Person With Cancer at Home

• Pain Control: Understanding and Managing Cancer Pain

National organizations and Web sites*

Along with the American Cancer Society, other sources of information and support include:

CancerCare
Toll-free number: 1-800-813-4673
Web site: www.cancercare.org
Offers counseling by phone, and support from others with cancer online and by phone. Cancer information also available

National Cancer Institute
Toll-free number: 1-800-422-6237 (1-800-4-CANCER)
TTY: 1-800-332-8615
Web site: www.cancer.gov
Offers information on cancer, treatment, and coping with symptoms

OncoLink
Web site: www.oncolink.org
Information on cancer and coping with symptoms

*Inclusion on this list does not imply endorsement by the American Cancer Society.

No matter who you are, we can help. Contact us anytime, day or night, for information and support. Call us at 1-800-227-2345 or visit www.cancer.org.

References

Hurter B, Bush NJ. Cancer-Related Anemia: Clinical Review and Management Update. Clinical Journal of Oncology Nursing. 2007; 11(3): 349-359.

National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology. Cancer- and Chemotherapy-Induced Anemia – V.2.2010. Accessed at: http://www.nccn.org/professionals/physician_gls/PDF/anemia.pdf on August 21, 2009.

Rosenbaum EH. Anemia causes and Treatment. From Cancer Supportive Care Web site. July 15, 2008. Accessed at www.cancersupportivecare.com/anemiacause.html on August 21, 2009.

Smith RE, Tchekmedyian S. Practitioners' Practical Model for Managing Cancer-Related Anemia. Oncology. 2002. 16(9 10). Accessed at: www.cancernetwork.com/display/article/10165/67853 on August 21, 2009.

Last Medical Review: 08/21/2009
Last Revised: 08/21/2009