Composed of red blood cells, white blood cells, blood platelets, proteins and blood plasma. Anemia: a decreased red blood cell or hemoglobin level in blood     There are different types of anemia: iron deficiency anemia, hemolytic anemia, aplastic nemia and thalassemia etc. A severe form of anemia The bone marrow failed to produce blood cells, which not only includes red blood cells, but also white blood cells and blood platelets. Unknown Over radiation reaction Chemistry Medication, for example antineoplastic drug and antibiotic etc. Most are inherited among child patients. Pallor Increased risk of infection Bleeding. e.g. nose bleeding White blood cells count < 500/mm3 Platelets count < 20000/mm3 Reticulocyte count < 1% Bone marrow biopsy shows few blood cells (< 30%) Blood transfusion Antibiotic Bone marrow transplantation Marrow-stimulating agents Immunosuppressive agents