Your FAQs Answered: How Does Beta Thalassemia Affect Your Blood?

Health Line

19-06-2025

Beta thalassemia is a blood condition that causes low levels of functional red blood cells, which may sometimes cause mild to severe anemia.
Beta thalassemia results from mutations in the HBB gene, which gives your body instructions for producing hemoglobin, a protein in red blood cells that carries oxygen. This leads to abnormal hemoglobin and defective red blood cells.
Beta thalassemia may cause mild to severe anemia, depending on the specific form of your condition. Severe anemia can cause life-threatening complications without treatment.
Read on to find the answers to your most pressing questions about beta thalassemia.
How does beta thalassemia affect the blood?
If you have beta thalassemia, your body produces fewer red blood cells than usual. Your red blood cells are also smaller than usual and may not contain enough functional hemoglobin.
Hemoglobin in red blood cells carries oxygen around your body, which your cells need to function properly.
When you don't have enough red blood cells with functional hemoglobin, your cells don't get enough oxygen. This is known as anemia. The condition can lead to tissue and organ damage.
Beta thalassemia may cause mild to severe anemia.
How serious is beta thalassemia?
There are three main forms of beta thalassemia, which range from mild to severe:
Beta thalassemia minor: This form of the condition may cause mild anemia.
Beta thalassemia intermediate: This form can cause mild to moderately severe anemia.
Beta thalassemia major: This form causes severe anemia, which can lead to potentially life-threatening complications without treatment.
If you inherit a mutation of the HBB gene from one parent, you'll develop beta thalassemia minor, also known as beta thalassemia trait. Most people with beta thalassemia trait never know they have it and don't require treatment.
If you inherit mutations of the HBB gene from both parents, you'll develop beta thalassemia intermediate or beta thalassemia major. Beta thalassemia major typically causes severe anemia within the first 2 years of life.
To treat severe anemia, your doctor will most likely prescribe blood transfusions. People with beta thalassemia major often require regular blood transfusions to survive.
People with beta thalassemia intermediate may require occasional blood transfusions.
Multiple blood transfusions can lead to hemochromatosis (iron overload), damaging your tissues and organs. Beta thalassemia can also contribute to iron overload by causing your body to absorb more iron than usual from food in your digestive tract.
Your doctor will prescribe iron-lowering medication to treat iron overload. This is known as iron chelation therapy.
What are the potential complications of beta thalassemia?
Severe anemia from beta thalassemia can cause complications, such as:
delay in growth and puberty in adolescents or preadolescents
sexual maturation delay
enlarged spleen or liver
atypical bone marrow expansion, which may cause brittle bones and structural changes in the bones
unusual masses in your spleen, liver, lymph nodes, chest, or spine
Iron overload from beta thalassemia or blood transfusions can also cause complications, such as damage to the:
heart, which may cause inflammation, atypical heart rhythms, and heart failure
liver, which may cause inflammation, scarring known as cirrhosis, and liver failure
endocrine glands, which may cause thyroid disease or, in rare cases, diabetes
Some of these complications are potentially life threatening.
The red blood cells in beta thalassemia are more likely to stick to each other, which increases the risk of blood clots in veins, known as venous thrombosis. Following a recommended treatment plan can lower your risk of complications.
Does beta thalassemia affect the immune system?
Beta thalassemia can affect your spleen, which is important to your immune system.
The spleen is an organ in your abdomen that helps control your level of blood cells. It also filters your blood and monitors it for certain infections.
Anemia from beta thalassemia may require your spleen to work harder than usual to produce red blood cells. As a result, it may not be able to filter your blood as well as it did before.
This increases the risk of certain infections.
Can beta thalassemia turn into leukemia?
A 2019 research review showed that experts need more research to learn how beta thalassemia and other forms of thalassemia affect the risk of cancers.
Evidence suggests that people with the intermediate or major form of beta thalassemia have an increased risk of blood cancers, including lymphoma and leukemia.
Iron overload from regular blood transfusions or beta thalassemia may help account for the increased cancer risk. Too much iron in your body can damage cells and increase the risk of cellular mutations.
Bloodborne viruses that raise the risk of certain cancers may also be transmissible to people through blood transfusions. The United States requires donor blood to get tests for some, but not all, types of viruses.
Beta thalassemia can also cause changes to your blood marrow, which might affect cancer risk.
How does beta thalassemia compare with alpha thalassemia?
Alpha thalassemia is another blood condition that causes low levels of functional hemoglobin. Alpha and beta thalassemia affect different parts of the hemoglobin protein.
Both conditions can cause anemia ranging from mild to severe, which may require blood transfusions to treat.
The most severe form of alpha thalassemia usually leads to death in newborns.
Takeaway
Beta thalassemia is a blood condition that causes low levels of functional hemoglobin.
Beta thalassemia minor often causes no symptoms and requires no treatment. Beta thalassemia intermediate may cause mild to moderately severe anemia, which may require occasional blood transfusions to treat. Beta thalassemia causes severe anemia, which often requires regular blood transfusions to prevent and treat.