Complications of Thalassemia

Both thalassemia major and thalassemia intermedia can cause more than just anemia. The complications associated with thalassemia are partially determined by the severity of your particular type of thalassemia and the treatment you require. Because thalassemia is a blood disorder, any organ can be affected.

Patient having discussion with physician in exam room
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Common Thalassemia Complications

Learning that you are at risk for serious medical complications due to your thalassemia may feel alarming. Know that maintaining regular medical care is key to screening for these complications and initiating early treatment. 

Skeletal Changes

Red blood cell (RBC) production occurs primarily in the bone marrow. In the case of thalassemia, this RBC production is ineffective. One way the body attempts to improve production is by expanding the available space in the bone marrow. This most notably occurs in the bones of the skull and face. People can develop what is called "thalassemic facies"—chipmunk-like cheeks and a prominent forehead. Early initiation of chronic transfusion therapy can prevent this from occurring.

Osteopenia (weak bones) and osteoporosis (thin and brittle bones) can occur in adolescents and young adults. It is not understood why these changes occur in thalassemia. The osteoporosis may be severe enough to cause fractures, particularly vertebral fractures. Transfusion therapy does not appear to prevent this complication.


The spleen is capable of producing red blood cells (RBC); it generally loses this function around the fifth month of pregnancy. In thalassemia, the ineffective RBC production in the bone marrow can trigger the spleen to resume production. In an attempt to do this, the spleen grows in size (splenomegaly).

This RBC production is not effective and does not improve anemia. Early initiation of transfusion therapy can prevent this. If the splenomegaly causes an increase in transfusion volume and/or frequency, splenectomy (surgical removal of the spleen) may be required.


Thalassemia is a hemolytic anemia, meaning the red blood cells are destroyed more rapidly than they can be produced. Destruction of the red blood cells releases bilirubin, a pigment, from the red blood cells. This excessive bilirubin may result in the development of multiple gallstones.

In fact, more than half of people with beta thalassemia major will have gallstones by age 15. If the gallstones cause significant pain or inflammation, gallbladder removal (cholecystectomy) may be required.

Iron Overload

People with thalassemia are at risk for developing iron overload, also called hemochromatosis. Excessive iron comes from two sources: repeated red blood cell transfusions and/or increased absorption of iron from foods.

Iron overload can cause significant medical problems in the heart, liver, and pancreas. Medications called iron chelators can be used to remove iron from the body. 

Aplastic Crisis

People with thalassemia (as well as other hemolytic anemias) require a high rate of new red blood cell production. Parvovirus B19 is a virus that causes a classic illness in children called Fifth Disease.

Parvovirus infects the stem cells in the bone marrow, preventing RBC production for 7 to 10 days. This decrease in RBC production in a person with thalassemia leads to the development of severe anemia and usually the need for RBC transfusion.

Endocrine Problems

The excessive iron overload in thalassemia can result in iron being deposited in the endocrine organs, such as the pancreas, thyroid, and sex organs. Iron in the pancreas can result in the development of diabetes mellitus. Iron in the thyroid can cause hypothyroidism (low thyroid hormone levels), which may result in fatigue, weight gain, cold intolerance (feeling cold when others do not), and coarse hair. Iron in the sex organs may lead to symptoms that include decreased libido and impotence in men and lack of menstrual cycles in women.

Heart and Lung Issues

Heart issues are not uncommon in people with beta thalassemia major. Enlargement of the heart occurs early in life due to anemia. With less blood, the heart needs to pump harder, causing enlargement. Transfusion therapy can help prevent this from occurring. Long-term iron overload in the heart muscle is a major complication. Iron in the heart can cause an irregular heartbeat (arrhythmia) and heart failure. Starting iron chelation therapy early is crucial to preventing these life-threatening complications.

Although the reasons why are not completely understood, people with thalassemia appear to be at risk for developing pulmonary hypertension, or high blood pressure in the lungs. When blood pressure is elevated in the lungs, it makes it more difficult for the heart to pump blood into the lungs, which can lead to heart complications. Symptoms can be subtle, and screening tests are crucial so that treatment can be started early.

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  • Benz EJ. Clinical manifestations and diagnosis of thalassemia. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA.
  • Standards of Care Guidelines for Thalassemia-2012.

By Amber Yates, MD
Amber Yates, MD, is a board-certified pediatric hematologist and a practicing physician at Baylor College of Medicine.