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Illustration of red blood cells

What is thalassemia?

Thalassemia (say "thal-uh-SEE-mee-uh") is an inherited blood disorder that causes your body to make less hemoglobin. Hemoglobin helps red blood cells spread oxygen through your body. Low levels of hemoglobin may cause anemia, an illness that makes you feel weak and tired. Severe anemia can damage organs and lead to death.

What causes thalassemia?

Thalassemia is passed from parent to child. A defect in one or more genes causes it. Both parents must carry a gene for the disease in order to pass it to their child.

What are the symptoms?

Mild thalassemia usually does not cause any symptoms.

If you have moderate or severe thalassemia, you may have signs of anemia, such as:

  • Feeling weak and tired.
  • Feeling faint.
  • Feeling less hungry and losing weight.
  • Skin that looks paler than normal.
  • Jaundice (skin and whites of the eyes appear yellow).
  • Dark urine.
  • A fast heartbeat.
  • Shortness of breath during exercise.

How is thalassemia diagnosed?

Your doctor will do an examination and ask about your health history. Tests include:

  • A complete blood count (CBC).
  • A gene test.
  • An iron level test, to find out whether you have iron deficiency anemia.
  • A blood test that measures the amounts of different types of hemoglobin, to help find out which type of thalassemia you have.
  • A complete blood count (CBC) test on other members of your family, to find out if they have thalassemia.

How is it treated?

Treatment depends on how severe your condition is.

  • Mild thalassemia, the most common form, does not need treatment.
  • Moderate thalassemia may be treated with folic acid supplements and blood transfusions.
  • Severe thalassemia may be treated with:
    • Blood transfusions.
    • Folic acid.
    • Surgery to remove the spleen.
    • A bone marrow transplant, in some severe cases.

If you are treated with blood transfusions, it’s possible for your body to get too much iron through repeated transfusions. This can damage your organs, especially the liver. If you have too much iron, your doctor may give you chelation therapy, which is a medicine that helps remove iron from your body.

What are the types of thalassemia?

There are two main types of thalassemia: alpha and beta. Beta thalassemia is the most common.

Beta thalassemia

You need both alpha- and beta-globin to make hemoglobin. Beta thalassemia occurs when one or both of the genes that make beta-globin don't work or only partly work as they should. It mainly affects people from the region around the Mediterranean Sea (such as Greeks and Italians). Less often, it affects people of African or Asian descent. And in the late 1970s there were cases reported in French-speaking Quebec families whose ancestors were not from the Mediterranean. There are several types of beta thalassemia.

Currently there is no general screening for thalassemia in Canada. If you are from an at-risk ethnic group and are considering having a child, talk to your doctor about the possibility of your child being born with thalassemia. You may be referred for genetic counselling.

  • If you have one damaged beta-globin gene, you may have mild anemia and probably will not need treatment. This condition is called beta thalassemia minor or beta thalassemia trait. This happens when you get a normal gene from one parent and a thalassemia gene from the other.
  • When both beta-globin genes are damaged, it means you got a thalassemia gene from each parent. You may have moderate or severe anemia.
    • If you have moderate anemia (beta thalassemia intermedia), you may need blood transfusions. People with this condition usually live into adulthood.
    • People with severe anemia (called beta thalassemia major or Cooley's anemia) usually do not live into adulthood without treatment. Symptoms of anemia usually begin within a few months after birth. A child who receives blood transfusions early and then throughout life is more likely to live longer.

Alpha thalassemia

Alpha thalassemia occurs when one or more of the four alpha-globin genes that make hemoglobin are missing or damaged. It mainly affects people from Southeast Asia, China, and the Philippines, but it sometimes affects people of African descent and can occur throughout the world.

There are four types of alpha thalassemia. Each type represents the loss of or damage to one, two, three, or four genes.

  • One gene: If one alpha-globin gene is missing or damaged, you will have no symptoms and will not need treatment. But you are a silent carrier. This means you don't have the disease but you can pass the defective gene to your child.
  • Two genes: If two alpha-globin genes are missing or damaged, you will have very mild anemia that will not need treatment. This is called alpha thalassemia minor or alpha thalassemia trait.
  • Three genes: If three alpha-globin genes are missing, you will have mild to moderately severe anemia. This is sometimes called hemoglobin H disease. If it is severe, you may need blood transfusions.
  • Four genes: If all four alpha-globin genes are missing (alpha thalassemia major), the fetus will be stillborn, or the child will die shortly after birth.

Frequently Asked Questions

Learning about thalassemia:

Being diagnosed:

Getting treatment:

Living with thalassemia:


Mild thalassemia usually does not cause any symptoms.

People who have more severe forms of the condition may develop symptoms of anemia, which may include:

  • Weakness.
  • Fatigue.
  • Light-headedness.
  • Skin that looks paler than normal.
  • Jaundice (skin and whites of the eyes appear yellow).
  • Dark urine.
  • Decreased appetite and weight loss (poor growth in a child).
  • A rapid heartbeat.
  • Shortness of breath during exercise.

Less common symptoms of severe thalassemia include:

  • Headache.
  • Belly pain.
  • Ringing in the ears.
  • Chest pain.
  • A slight fever.
  • A sore, smooth tongue.

Children with a more severe form of thalassemia (beta thalassemia major, or Cooley's anemia) usually have symptoms of anemia within the first few months of life. Paler skin is often the first sign of the disease. Infants may grow slowly (failure to thrive). Other symptoms may include feeding problems, frequent fevers, and diarrhea. Without early treatment, a child may die or develop severe problems, such as:

  • A deformed face caused by the bone marrow expanding in the bones. This may cause a bulging forehead (frontal bossing).
  • An enlarged liver and spleen.
  • Brittle, weak bones (most often the long bones in legs and arms and the bones of the spine).

Related problems of severe thalassemia may include:

  • Severe bacterial infections. An annual flu shot and the pneumonia vaccine may protect you from severe infections, which can make anemia worse in people with thalassemia.
  • Organ damage. Many blood transfusions over time can lead to higher levels of iron stored in the body. The body stores this excess iron in the liver, heart, and other organs. In time, too much iron in these organs (iron overload) may cause damage. To reduce the amount of iron in your body, your doctor may treat you with chelating therapy, which is a medicine that removes the extra iron in your body.

Examinations and Tests

A physical examination and complete medical history are usually the first steps in diagnosing thalassemia. Your medical history includes:

  • Your symptoms.
  • Your ethnic background.
  • The general health of close family members.
  • Any other health conditions you may have.
  • Any blood tests that you have had.

Results of tests reveal important information, such as the type of thalassemia. Tests that help confirm a diagnosis of thalassemia include:

  • Complete blood count (CBC) and blood smear.
    • Blood cells are checked for their shape, colour, number, and size. These features help your doctor know whether you have thalassemia and, if so, what type.
    • These tests also tell your doctor if you have mild, moderate, or severe anemia.
  • Tests for the genes that often cause thalassemia.
  • Blood tests that measure the amount of iron in the blood (iron level tests and a ferritin test).
  • A blood test that measures the amounts of different types of hemoglobin (hemoglobin electrophoresis). The results help determine the type of thalassemia you have.
  • A complete blood count (CBC) on other members of your family (parents and siblings). The results determine whether they have thalassemia.

Doctors often diagnose the most severe form of thalassemia (beta thalassemia major, or Cooley's anemia) during the first year of a child's life.

Treatment Overview

Treatment for thalassemia depends on the severity of the condition. Thalassemia may be mild, moderate, or severe.

Mild thalassemia is the most common form and does not require treatment.

Moderate thalassemia (thalassemia intermedia and more severe hemoglobin H disease) may be treated with:

  • Folic acid (a vitamin that your body needs to produce new red blood cells). People with thalassemia often lack enough folic acid in their diets to keep a good supply of red blood cells.
  • Blood transfusions. You may need a blood transfusion when your body is under stress, such as during an infection.

If you have moderate thalassemia, do not take medicines that increase the amount of iron in the body, which can damage organs. These medicines include:

  • Iron supplements or multivitamins that contain iron.
  • Vitamin C, which can increase the amount of iron that your body absorbs from food.

Severe thalassemia is often treated with:

  • Regular blood transfusions. A child with severe thalassemia typically starts to have symptoms when he or she is 6 months old and will need blood transfusions every 4 to 6 weeks. The transfusions often lead to increased iron levels, which also may require treatment.
  • Folic acid, which your body needs to produce red blood cells. A person with thalassemia needs folic acid supplements because red blood cells are destroyed faster than normal. As a result, the body often uses up its stores of this vitamin.

Other treatments that doctors consider for severe cases of thalassemia include:

  • A splenectomy, which is surgical removal of the spleen.
  • In rare cases, a bone marrow transplant. This treatment can cure severe thalassemia, but it must be done before problems related to excess iron stored in the body develop. Phlebotomy, removing blood from the body, is sometimes needed after a successful bone marrow transplant, to reduce high iron levels.
  • Umbilical cord stem cell transplant. This procedure involves taking stem cells from the umbilical cord of a newborn. These stem cells are then injected into a child who has severe thalassemia. The donor is most often a brother or sister of the child. But the umbilical cord can also come from an unrelated donor from an umbilical cord blood bank.

What to Think About

Blood transfusion therapy often creates an excess of iron. An excess of iron, if untreated, may damage organs. You may need to use medicines called chelating agents that bind to and remove excess iron from the blood. The chelating agent deferasirox (Exjade) is taken as a pill once a day. The chelating agent deferoxamine mesylate (Desferal) is injected through a tube placed under the skin. A portable pump delivers the medicine in what is usually an all-night procedure. This treatment works best if it is done 5 or 6 nights a week. Both deferoxamine and deferasirox have potentially serious side effects, including hearing loss and kidney, liver, and eye problems.

Researchers are studying how well medicines (hydroxyurea and butyrate) work to get the body to produce fetal hemoglobin in children and adults who have thalassemia. Fetal hemoglobin is different from adult hemoglobin. The body does not normally produce it after birth. Fetal hemoglobin may help adult hemoglobin work better in people who have thalassemia.

Home Treatment

If you have blood transfusions to treat your thalassemia, you need to avoid vitamins that increase iron stored by the body. Excess iron can cause serious damage to your organs. Avoid the following vitamins:

  • Multivitamins that contain iron.
  • Vitamin C, which can increase the amount of iron you absorb from food.

You may want to get flu shots once a year. Talk to your doctor about getting a pneumonia shot. These shots may protect you from severe infections, which can make anemia worse in people who have thalassemia.

It is also important to get help from people who are specially trained in the medical and emotional effects of thalassemia. Talk to your doctor about groups that can help you cope with the impact this disease has on you and your family.

If you or any of your family members (parents or siblings) have thalassemia or thalassemia trait and you are thinking about having a child, you may want to talk to a health professional who specializes in the study of inherited disorders (genetic counsellor) before you become pregnant. A genetic counsellor can tell you how likely it is that your child will have thalassemia and how severe it might be.

Other Places To Get Help

Online Resources

Canadian Association of Genetic Counsellors (CAGC)
Web Address:

The Canadian Association of Genetic Counsellors (CAGC) is a professional organization of genetic counsellors, physicians, social workers, and students in related fields.

Canadian Directory of Genetic Support Groups
Canadian Association of Genetic Counsellors (CAGC) and the Children's Hospital at London Health Sciences Centre
Web Address:

The Canadian Directory of Genetic Support Groups provides a resource guide for families and professionals seeking information on genetic support groups in Canada.


Anemia Institute
151 Bloor Street West
Suite 600
Toronto, ON  M5S 1S4
Phone: (416) 969-7431
Fax: (416) 969-7420
Web Address:

Anemia Institute provides education, information, and support services among patients and health professionals about all aspects of anemia.

Cooley's Anemia Foundation
330 Seventh Avenue
Suite 900
New York, NY  10001
Phone: 1-800-522-7222
Fax: (212) 279-5999
Web Address:

Cooley's Anemia Foundation is a nonprofit organization dedicated to serving people afflicted with various forms of thalassemia, most notably the major form of this genetic blood disease, Cooley's anemia (thalassemia major). The foundation's mission is to advance the treatment and cure for thalassemia, enhance the quality of life of people who have it, and educate the medical profession, trait carriers, and the public about this fatal blood disease. The foundation encourages donations of blood, since thalassemia patients are the single largest users of blood supplies in the nation, and also sponsors chapters and support groups.

Iron Disorders Institute
P.O. Box 675
Taylors, SC  29687
Phone: 1-888-565-IRON (1-888-565-4766)
(864) 292-1175
Fax: (864) 292-1878
Web Address:

The Iron Disorders Institute is a national voluntary health agency that provides information about iron disorders such as hemochromatosis, acquired iron overload, sickle cell anemia, thalassemia, iron deficiency anemia, and anemia of chronic disease. The organization works with a scientific review board as well as various medical professional groups. A free newsletter, idInsight, is available.

Thalassemia Foundation of Canada
338 Falstaff Avenue
North York, ON  M6L 3E7
Phone: (416) 242-THAL [(416) 242-8425]
Fax: (416) 242-THAL [(416) 242-8425]
Web Address:

Thalassemia Foundation of Canada provides resource referrals, support, and education to patients and family members of those with thalassemia.


Other Works Consulted

  • Borgna-Pignatti C, Galanello R (2009). Thalassemias and related disorders: Quantitative disorders of hemoglobin synthesis. In JP Greer et al., eds., Wintrobe's Clinical Hematology, 12th ed., vol. 1, pp. 1083–1131. Philadelphia: Lippincott Williams and Wilkins.
  • Hillman RS, Ault KA (2005). Thalassemia. In Hematology in Clinical Practice, 4th ed., pp. 65–79. New York: McGraw-Hill.
  • Vadolas J, et al. (2004). Cellular genomic reporter assays for screening and evaluation of inducers of fetal hemoglobin. Human Molecular Genetics, 13(2): 223–233.
  • Weatherall DJ (2006). Disorders of globin synthesis: The thalassemias. In M Lichtman et al., eds., Williams Hematology, 7th ed., pp. 633–666. New York: McGraw-Hill.


By Healthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer Brian Leber, MDCM, FRCPC - Hematology
Last Revised October 21, 2009

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.