Donating Blood, Platelets or Bone Marrow Donating Blood Some cancer treatments reduce the number of blood cells, especially red blood cells, which can make the patient weak and anemic. A single unit of blood can be used to help one person or it can be separated into components and used to help several people. Donating blood is easy and safe! The entire process takes about an hour. Get more information about donating blood. Donating Platelets Platelets are blood cells that help control bleeding. Chemotherapy and radiation treatments often interfere with the body's production of platelets. Patients with leukemia don’t have enough platelets because their bone marrow has been damaged. Without regular platelet transfusion, these patients could hemorrhage. Transfusions of platelets help keep them alive while allowing time for their treatments to fight cancer. Platelets have a shelf-life of just five days from donation to infusion into a patient so there’s a constant need for more platelet donors. Donating platelets takes longer than donating whole blood, but the process is equally easy and safe. Get more information about donating platelets. Donating Bone Marrow Bone marrow is the source of all blood cells—red cells, white cells, and platelets. Bone marrow transplantation may be the only hope for patients with primary bone marrow failure or with malignancies of the bone marrow and lymph nodes, such as leukemia and lymphomas. The marrow collection process is a surgical procedure that occurs in a hospital operating room while you receive general or regional anesthesia. Get more information about donating bone marrow.