A bone marrow transplant is a medical procedure that replaces damaged or diseased bone marrow with healthy cells. Bone marrow is the soft tissue inside bones that produces blood cells, including red blood cells, white blood cells, and platelets. This treatment is often used for conditions like leukemia, lymphoma, and certain blood disorders. The transplant can involve using the patient's own cells, known as an autologous transplant, or cells from a donor, called an allogeneic transplant. Before the procedure, patients may undergo chemotherapy or radiation to prepare their bodies. After the transplant, patients need close monitoring to ensure their bodies accept the new cells and to manage any potential complications.