Certain diseases and disorders destroy bone marrow or cause it to function abnormally. Given that bone marrow produces blood, the life of a person with malfunctioning bone marrow is at risk. Treatment can involve replacing the patient's bone marrow through a stem cell transplant using donated bone marrow, peripheral blood stem cells or cord blood. You may be more familiar with the term bone marrow transplant as opposed to stem cell transplant, but the same stem cells are found in our peripheral blood and umbilical cord blood. The source of the stem cells selected depends on the patient's needs.

To prepare for a transplant, the recipient is usually given high doses of radiation, chemotherapy, or both, to destroy the diseased marrow. Patients who receive a stem cell transplant must remain isolated in a sterile room until the transplant has been successful and their new bone marrow has produced sufficient white blood cells to protect their system against surrounding bacteria.

A stem cell transplant is not the only solution for diseases such as leukemia and other cancers that result in the abnormal functioning of bone marrow. Treatments such as chemotherapy, radiotherapy and specialized medications are tried first to attempt to stop the disease. However, in some cases, these treatments do not work, and the only way to save a patient is to replace their stem cells with those from a person in good health.