Aplastic anemia is a heterogeneous disease characterized by a decrease in the number and quality of hematopoietic stem cells and by bone marrow hematopoietic failure, with clinical manifestations of infection, anemia, and bleeding. Patients with severe reblastosis are particularly critical if their neutrophils are <0.5×109/L or platelets are <20×109/L. Since the natural course of the disease is only 3-6 months, patients who do not receive timely and aggressive treatment usually die from severe infection or bleeding, with a very high mortality rate. Therefore, it is especially important to treat patients with severe reoccurrence as early as possible. Severe co-infection in patients with severe reoccurrence is closely associated with severe neutrophil deficiency, and severe and persistent neutropenia in patients is an important cause of severe infection. A study statistically analyzing the data of patients with reoccurrence found that infection was the leading cause of death in patients. Infections in patients with severe reoccurrence are not only more serious than normal infections and progress rapidly, but due to severe neutrophil deficiency, treatment with ordinary antibiotics is ineffective and requires advanced and powerful antibiotic therapy to achieve better results. More problematic is that severe neutrophil deficiency predisposes patients to fungal infections, and antifungal therapy is expensive and lengthy, which also interferes with further treatment and significantly increases the risk of hematopoietic stem cell transplantation or immunosuppressive therapy. Bleeding is another important cause of death in patients with severe reoccurrence. In addition to some patients who die of bleeding due to failure to transfuse platelets in a timely manner, most patients die of ineffective platelet transfusion due to repeated platelet transfusions resulting in the production of large amounts of platelet antibodies, and some patients may even experience lower and lower platelet transfusions, resulting in a long-term platelet count of <10×109/L. In this case, if the patient is combined with infection and fever or trauma bleeding, especially head injury, it is very difficult to stop bleeding after bleeding, and some patients will die as a result. Therefore, patients with heavy reoccurrence should go to an experienced reoccurrence treatment center for diagnosis and treatment of the disease as early as possible and undergo hematopoietic stem cell transplantation or immunosuppressive therapy as soon as possible to obtain the best results.