The most common complications after hematopoietic stem cell transplantation are as follows: 1. In the acute phase, that is, within 100 days after allogeneic hematopoietic stem cell transplantation, acute rejection will occur, called acute graft-versus-host disease. Some patients will show poor nausea, diarrhea, especially the kind of watery diarrhea or diarrhea, can not be stopped with ordinary drugs; another is jaundice, such as liver damage and jaundice, the patient will show yellow skin mucous membrane, check the liver function bilirubin is higher, and then transaminases are sometimes elevated; another performance is a rash, such as palms, feet, chest and back rash, these are acute graft-versus-host disease 2. Infection, because before allogeneic HSCT, pretreatment, i.e. a very intensive chemotherapy, after chemotherapy, the bone marrow is emptied, i.e. the cells in the bone marrow are removed, and at this time the blood count is almost zero, and then the platelet count is also very low, so infection and bleeding may occur. Infections are manifested as various kinds of infections, such as bacterial, viral, and fungal infections. Generally all parts of the body will bleed, in this case it is necessary to carry out active anti-infection treatment, including many advanced antibiotic applications, and then another is bleeding is mainly treated by platelet transfusion, platelet transfusion is carried out in the case of low platelets, if the coagulation function is abnormal, other blood products can also be transfused; another manifestation is bleeding cystitis, such as bleeding in the urinary tract, in fact, this may be 3, for some patients more than 100 days may appear some chronic rejection, that is, some manifestations of chronic graft-versus-host disease, generally will also be like skin mucous membrane damage, some joint damage, cataracts, and even arthritis, a variety of autoimmune disease manifestations, generally these clinical manifestations.