Thalassemia is a blood disorder caused by a genetic defect that results in inadequate hemoglobin production. It is most common in populations from the Mediterranean, Middle East, Africa, and Asia. There are two main types - alpha and beta thalassemia. Management involves regular blood transfusions to correct anemia, along with iron chelation therapy to prevent iron overload. Nursing care focuses on monitoring for complications, providing transfusions and chelation therapy, and educating patients and their families.