(Mediterranean Anemia; Cooley's Anemia; Thalassemia Major; Thalassemia Minor)

Pronounced: Thal-uh-SEE-mee-uh


Thalassemia is a blood disorder. It cuts down the amount of red blood cells and hemoglobin that the body can make. Red blood cells carry oxygen to all the organs in the body. Hemoglobin is a part of red blood cells that help grab oxygen at the lungs. Low levels of red blood cells and hemoglobin and abnormal hemoglobin can lead to anemia and difficulty carrying oxygen. Anemia interferes with normal bodily functions.


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Thalassemias are split into 2 main categories. The categories are based on the part of hemoglobin that is affected:

  • Alpha thalassemia—based on abnormality of the alpha part of hemoglobin
  • Beta thalassemia—based on abnormality of the beta part of hemoglobin

Causes    TOP

Thalassemia is caused by faults in specific genes. It is an inherited disorder. This means the affected person received the faulty genes from the parents. The severity of the thalassemia will depend on the number of faulty genes that a child inherits. There are 4 genes needed for hemoglobin, 2 from each parent. The number of genes that are faulty will determine the severity and subtype of thalassemia:

  • In alpha thalassemia:
    • 1 abnormal gene—silent carrier, no signs of illness but can pass condition on to child
    • 2 abnormal genes—thalassemia trait, may have mild anemia
    • 3 abnormal genes—Hemoglobin H disease, moderate to severe anemia
    • 4 abnormal genes—most severe form called Alpha hydrops fetalis, results in fetal or newborn death
  • In beta thalassemia:
    • 1 abnormal gene—Thalassemia minor, carrier with mild anemia
    • 2 abnormal genes—Thalassemia major known as Cooleys anemia, may have moderate to severe anemia

Risk Factors    TOP

Factors that increase your chance of thalassemia include:

  • Certain types of thalassemia may be associated with ancestors from certain parts of the world:
    • Alpha thalassemias—Middle East, areas surrounding the Mediterranean Sea, Southeast Asia, Malaysia, and Southern China
    • Alpha hydrops fetalis—Southeast Asian, Chinese, and Filipino ancestry
    • Beta thalassemias—Africa, areas surrounding the Mediterranean Sea, and Southeast and Central Asia
  • A family history of the disorder

Symptoms    TOP

Silent carriers will have no symptoms. For others, symptoms most often begin within 3-6 months of birth.

Symptoms of mild or moderate anemia may include:

  • Feeling weak and tired
  • Shortness of breath
  • Lightheadedness or headaches
  • Cold hands and feet
  • Pale skin

Symptoms of severe anemia include:

  • Lack of interest in activity
  • Pale appearance
  • Poor appetite/feeding
  • Dark urine
  • Jaundice

General findings of thalassemia may include:

  • Slow growth and delayed puberty
  • Enlarged and fragile bones, including:
    • Thickening and roughening of facial bones
    • Bones that break easily
    • Teeth that don't line up properly

Thalassemia can also lead to complications such as:

  • Increased risk of developing infections
  • Enlarged spleen
  • Heart failure
  • Liver problems

Diagnosis    TOP

You will be asked about your symptoms and medical history. A physical exam will be done.

Blood tests will be done to analyze your hemoglobin and measure levels of:

  • Hemoglobin
  • Red blood cells
  • Iron

Genetic testing may help make the diagnosis in some types of thalassemia

Treatment    TOP

Treatment will be based on the type and severity of anemia. Mild forms may not need treatment. More severe forms may need:

Blood Transfusions

Blood transfusions will help provide healthy new red blood cells. The blood comes from a donor and is carefully screened before it is delivered in a transfusion.

Repeated blood transfusions can lead to high levels of iron in the blood. This can damage the heart, liver, and other vital organs. Certain medications can bind to the iron and carry it out of the body through urine.

Bone Marrow Transplant

Healthy stem cells from a donor's bone marrow are injected into a vein. The new cells travel through the blood into the bone cavities. There, they can produce new normal blood cells. This may be a cure in some. However, it can be hard to find a good match with a donor and there are many complications.

Splenectomy    TOP

Thalassemia can cause the spleen to enlarge. An enlarged spleen can make anemia worse. A splenectomy is a surgery to remove the spleen. It may help reduce the number of blood transfusions that are needed.

General Health    TOP

Complications and impact on your daily activities may be reduced by following basic healthy lifestyle tips:

  • Eat a well balanced diet. Your doctor may also recommend supplements like folic acid.
  • Include regular physical activity.
  • Take steps to prevent cold or flu. Wash your hand often. Avoid crowds in flu season. Get vaccinations as recommended.
  • If you have thalassemia and you are pregnant, talk to you doctor about any special steps you need to take.
  • Go to all medical appointments as recommended.

Prevention    TOP

This disease is inherited. Blood tests and family genetic studies will show if you are a carrier. A genetic counselor can discuss the risks of passing on the disease.


Northern California Comprehensive Thalassemia Center
National Heart, Lung, and Blood Institute


Canadian Hemophilia Society
The Thalassemia Foundation of Canada


Alpha-thalassemia. EBSCO DynaMed Plus website. Available at: Updated October 23, 2015. Accessed August 24, 2017.
Beta-thalassemia major and intermedia. EBSCO DynaMed Plus website. Available at: http://www.dynamed.... Updated June 6, 2016. Accessed August 24, 2017.
Beta-thalassemia minor. EBSCO DynaMed Plus website. Available at: http://www.dynamed.... Updated October 23, 2016. Accessed August 24, 2017.
Explore thalassemias. National Heart, Lung, and Blood Institute website. Available at:
...(Click grey area to select URL)
Updated July 3, 2012. Accessed August 24, 2017.
Hydrops fetalis. EBSCO DynaMed website. Available at:
...(Click grey area to select URL)
Updated August 5, 2015. Accessed August 24, 2017.
4/24/2014 DynaMed Plus Systematic Literature Surveillance Thalassaemia in pregnancy, Management of Beta (Green-top 66). Royal College of Obstetrians and Gynaecologists website. Available at: Published March 27, 2014. Accessed September 19, 2017.
Last reviewed September 2017 by EBSCO Medical Review Board Michael Woods, MD, FAAP
Last Updated: 8/24/2017

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