A lack of oxygen in the bloodstream causes the signs and symptoms of thalassemias. The lack of oxygen occurs because the body doesn't make enough healthy red blood cells and hemoglobin. The severity of symptoms depends on the severity of the disorder.
                
No Symptoms
                
Alpha thalassemia silent carriers generally have no signs or symptoms of the disorder. The lack of alpha globin protein is so minor that the body's hemoglobin works normally.
                
Mild Anemia
                
People who have alpha or beta thalassemia trait can have mild anemia. However, many people who have these types of thalassemia have no signs or symptoms.
                
Mild anemia can make you feel tired. Mild anemia caused by alpha thalassemia trait might be mistaken for iron-deficiency anemia.
                
Mild to Moderate Anemia and Other Signs and Symptoms
                
People who have beta thalassemia intermedia have mild to moderate anemia. They also may have other health problems, such as:
                
Slowed growth and delayed puberty. Anemia can slow down a child's growth and development.
                
Bone problems. Thalassemia may cause bone marrow to expand. Bone marrow is the spongy substance inside bones that makes blood cells. When bone marrow expands, the bones become wider than normal. They may become brittle and break easily.
                
An enlarged spleen. The spleen is an organ that helps your body fight infection and remove unwanted material. When a person has thalassemia, the spleen has to work very hard. As a result, the spleen becomes larger than normal. This makes anemia worse. If the spleen becomes too large, it must be removed.
                
Severe Anemia and Other Signs and Symptoms
                
People who have hemoglobin H disease or beta thalassemia major (also called Cooley's anemia) have severe thalassemia. Signs and symptoms usually occur within the first 2years of life. They may include severe anemia and other health problems, such as:
                
A pale and listless appearance
                
Poor appetite
                
Dark urine (a sign that red blood cells are breaking down)
                
Slowed growth and delayed puberty
                
Jaundice (a yellowish color of the skin or whites of the eyes)
                
An enlarged spleen, liver, or heart
                
Bone problems (especially with bones in the face)
                
Complications of Thalassemias
                
Better treatments now allow people who have moderate and severe thalassemias to live much longer. As a result, these people must cope with complications of these disorders that occur over time.
                
Heart and Liver Diseases
                
Regular blood transfusions are a standard treatment for thalassemias. Transfusions can cause iron to build up in the blood (iron overload). This can damage organs and tissues, especially the heart and liver.
                
Heart disease caused by iron overload is the main cause of death in people who have thalassemias. Heart disease includes heart failure, arrhythmias (irregular heartbeats), and heart attack.
                
Infection
                
Among people who have thalassemias, infections are a key cause of illness and the second most common cause of death. People who have had their spleens removed are at even higher risk because they no longer have this infection-fighting organ.
                
Osteoporosis
                
Many people who have thalassemias have bone problems, including osteoporosis (OS-te-o-po-RO-sis). This is a condition in which bones are weak and brittle and break easily.