There are two main types of thalassemia: alpha thalassemia and beta thalassemia. Each type has different subtypes, which can vary in severity.

1.Alpha Thalassemia: This type occurs when there is a problem with the production of alpha globin chains, a component of hemoglobin. The severity of alpha thalassemia depends on the number of affected genes. Subtypes include silent carrier, alpha thalassemia trait, hemoglobin H disease, and hydrops fetalis.

2.Beta Thalassemia: Beta thalassemia occurs when there is a mutation or absence of the beta globin chains. The severity of beta thalassemia can range from mild to severe. Subtypes include thalassemia minor, thalassemia intermedia, and thalassemia major (also known as Cooley’s anemia).