Medical GVHD is an acronym for graft-versus-host disease. Graft-versus-host disease refers to a series of symptoms that occur after allogeneic hematopoietic stem cell transplantation due to donor T lymphocytes attacking various tissues and organs of the recipient, and graft-versus-host disease is one of the hallmarks of successful clinical transplantation. Common sites of attack for graft-versus-host disease include damage to the skin, damage to the digestive tract, and damage to liver function. Skin lesions can manifest as maculopapular skin rashes, and in severe cases, blisters as well as skin exfoliation and generalized erythrodermia. The severity of graft-versus-host disease is classified as Grade I-IV, and it can also cause diarrhea, which can be watery stools. In severe cases, liver damage may occur, leading to increased bilirubin concentration, jaundice and increased transaminase concentration. Methotrexate, cyclosporine and methylprednisolone can be used to prevent graft-versus-host disease.