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

Pronounced: Thal-uh-SEE-mee-uh


Thalassemia is a blood disorder. It lowers the number of healthy red blood cells in the body. Red blood cells carry oxygen to all the organs in the body. Low levels make it hard to get enough oxygen throughout the body.

Hemoglobin is an important part of red blood cells. It is needed for red blood cells to pick up oxygen. Hemoglobin is abnormal in thalassemias. The type of thalassemia will depend on what part of the hemoglobin is affected:

  • Alpha thalassemia—alpha part of hemoglobin is damaged
  • Beta thalassemia—beta part of hemoglobin is damaged


Copyright © Nucleus Medical Media, Inc.


Thalassemia is caused by problems in specific genes. The altered gene or genes are passed from the parents. There are 4 genes needed for changes in hemoglobin, 2 from each parent. The number of genes that are passed will decide how severe thalassemia is:

  • In alpha thalassemia:
    • 1 abnormal gene—no signs of illness but can pass condition on to their child; called silent carrier
    • 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

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 most often begin within 3 to 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
  • Yellowing of skin and white of eye (jaundice)

Thalassemia can also lead to complications such as:

  • 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
  • Frequent infections
  • Enlarged spleen
  • Heart failure
  • Liver problems

Silent carriers will have no symptoms.


You will be asked about symptoms and health history. A physical exam will be done. A blood test will measure levels of:

  • Hemoglobin
  • Red blood cells
  • Iron

Anemia can be diagnosed after blood tests. Further tests of hemoglobin will show thalassemia. Genetic testing may help make the diagnosis for those that are silent carriers.


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 is collected from a healthy donor. It is carefully screened and treated, then delivered to recipient. The transfusions will immediately increase the number of healthy red blood cells.

Bone Marrow Transplant

Blood cells are formed in the bone marrow. A bone marrow transplant uses healthy cells from a donor to grow new bone marrow. This can let the body grow healthy red blood cells. It may be a cure for some people. However, there can be complications from this type of procedure. It can also be hard to find a good match with a donor. It may not be an option for everyone.


The spleen is a small organ near the stomach. It helps to recycle old red blood cells. Anemia can enlarge the spleen. This can make anemia worse. The spleen may need to be removed. The surgery may help cut back on the number of blood transfusions that are needed.

General Health

Extra stress on your body can make you feel worse. Basic steps can help improve your overall health and reduce stress on your body:

  • Eat a well balanced diet. Your doctor may also recommend supplements like folic acid.
  • Exercise at least 3 to 5 days per week. There are many options to help work with joint pain or other health limits.
  • 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.

Special steps will be needed during pregnancy. It is important to make sure a care team knows about thalassemia.


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 September 6, 2019.
Beta-thalassemia major and intermedia. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated June 13, 2019. Accessed September 6, 2019.
Beta-thalassemia minor. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated August 15, 2019. Accessed September 6, 2019.
Explore thalassemias. National Heart, Lung, and Blood Institute website. Available at:
...(Click grey area to select URL)
Accessed September 6, 2019.
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 2019 by EBSCO Medical Review Board Michael Woods, MD, FAAP
Last Updated: 9/6/2019

EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

To send comments or feedback to our Editorial Team regarding the content please email us at Our Health Library Support team will respond to your email request within 2 business days.