The sponge-like, soft tissue within certain bones of the body, which produces blood cells, is called bone marrow. In a bone marrow transplant or a stem cell transplant, faulty or diseased marrow is replaced with the healthy counterpart. It is a treatment modality for certain types of cancer.

In a bone marrow transplant, a donor's healthy blood-forming cells are transfused into the recipient's bone marrow, where it starts growing and make healthy white blood cells, red blood cells, and platelets. This treatment is provided after completing radiation and chemotherapy in cancer. A central venous catheter is used to deliver stem cells into the recipient's bloodstream.

The blood cell count of a recipient drops significantly in approximately 3-10 days. Radiation is used for preparing the patient for stem cell transplant. It targets cancer cells and may also suppress the immune system. It usually takes 24 hours for the transfused stem cells to reach the bone marrow, after which they start growing and help to make healthy blood cells.

Most platelets, red blood cells and white blood cells are formed in the red marrow. Erythropoietin, which is produced in the kidneys, is released, and it stimulates the bone marrow to produce more red blood cells. Eating a diet rich in proteins helps to build bone marrow naturally.

Factors, such as the transplant type and the patient's medical condition, influence the recovery time after bone marrow transplant. Usually, it takes 2-6 weeks. The patient will have to be in the hospital or visit the transplant centre daily for at least a few weeks.