A bone marrow transplant is a procedure that infuses healthy blood-forming stem cells into your body to replace bone marrow that's not producing enough healthy blood cells. A bone marrow transplant is also called a stem cell transplant.

You might need a bone marrow transplant if your bone marrow stops working and does not produce enough healthy blood cells.

Bone marrow transplants may use cells from your own body (autologous transplant) or from a donor (allogeneic transplant).

A bone marrow transplant may be used to:

• Safely allow treatment with high doses of chemotherapy or radiation by replacing or rescuing the bone marrow damaged by the treatment
• Replace bone marrow that's not working properly with new stem cells
• Provide new stem cells, which can help kill cancer cells directly

Bone marrow transplants can benefit people with a variety of both cancerous and noncancerous diseases, including:

• Acute leukemia
• Adrenoleukodystrophy
• Aplastic anemia
• Bone marrow failure syndromes
• Chronic leukemia
• Hemoglobinopathies
• Hodgkin's lymphoma
• Immune deficiencies
• Inborn errors of metabolism
• Multiple myeloma
• Myelodysplastic syndromes
• Neuroblastoma
• Non-Hodgkin's lymphoma
• Plasma cell disorders
• POEMS syndrome
• Primary amyloidosis

Collecting stem cells for allogeneic transplant

If you're having a transplant using stem cells from a donor (allogeneic transplant), you'll need a donor. Once a donor is found, stem cells are gathered from that person for the transplant.

Stem cells can come from your donor's blood or bone marrow. Your transplant team decides which is better for you based on your situation.

Another type of allogeneic transplant uses stem cells from the blood of umbilical cords (cord blood transplant). Mothers can choose to donate umbilical cords after their babies' births. The blood from these cords is frozen and stored in a cord blood bank until needed for a bone marrow transplant.

The conditioning process

After completing the pretransplant tests and procedures, you'll begin a process known as conditioning. During conditioning, you'll undergo chemotherapy and possibly radiation to:

• Destroy cancer cells if you're being treated for cancer that may spread to other parts of the body
• Suppress your immune system
• Prepare your bone marrow for the new stem cells

The type of conditioning process you receive depends on several factors, including the disease being treated, your overall health and the type of transplant planned. You may have both chemotherapy and radiation or just one of these treatments as part of your conditioning treatment.

Side effects of the conditioning process can include:

• Nausea and vomiting
• Diarrhea
• Hair loss
• Mouth sores or ulcers
• Infection
• Bleeding
• Infertility or sterility
• Anemia
• Fatigue
• Cataracts
• Organ complications, such as heart, liver or lung failure

You may be able to take medications or other measures to reduce such side effects.

Reduced-intensity conditioning

Based on your age and health history, you may receive lower doses or different types of chemotherapy or radiation for your conditioning treatment. This is called reduced-intensity conditioning.

Reduced-intensity conditioning kills some cancer cells and suppresses your immune system. Then, the donor's cells are infused into your body. Donor cells replace cells in your bone marrow over time. Immune factors in the donor cells may then fight your cancer cells.

During your bone marrow transplant

Your bone marrow transplant occurs after you complete the conditioning process. On the day of your transplant, stem cells are infused into your body through your central line.

The transplant infusion is painless. You'll be awake during the procedure.

After your bone marrow transplant

When the new stem cells enter your body, they travel through your blood to your bone marrow. In time, they multiply and begin to make new, healthy blood cells. This is called engraftment. It usually takes several weeks before the number of blood cells in your body starts to return to the standard range. In some people, it may take longer.

In the days and weeks after your bone marrow transplant, you'll have blood tests and other tests to monitor your condition. You may need medicine to manage complications, such as nausea and diarrhea.

After your bone marrow transplant, you'll remain under close medical care. If you're experiencing infections or other complications, you may need to stay in the hospital for several days or longer. Depending on the type of transplant and the risk of complications, you'll need to remain near the hospital for several weeks to months to allow close monitoring.

You may also need periodic transfusions of red blood cells and platelets until your bone marrow begins producing enough of those cells on its own.

You may be at greater risk of infections or other complications for months to years after your transplant. For the rest of your life, you'll meet regularly with your health care provider to check for late complications.

Medications

If your bone marrow transplant is using stem cells from a donor (allogeneic transplant), you may take medications to help prevent graft-versus-host disease (GVHD) and reduce your immune system's reaction. These drugs are called immunosuppressive medications.

After your transplant, it takes time for your immune system to recover. During this time, you may be given medications to prevent infections.

Diet and other lifestyle factors

After your bone marrow transplant, you may need to adjust your diet to stay healthy and to prevent excessive weight gain. Your nutrition specialist (dietitian) and other members of your transplant team will work with you to create a healthy-eating plan that meets your needs and complements your lifestyle. Your dietitian can also give you food suggestions to control side effects of chemotherapy and radiation, such as nausea.

Your dietitian can also give you food suggestions to control side effects of chemotherapy and radiation, such as nausea.

Some of your dietitian's recommendations may include:

• Following food safety guidelines to prevent foodborne infections
• Eating a wide variety of healthy foods, including vegetables; fruits; whole grains; lean meats, poultry and fish; legumes; and healthy fats, such as olive oil
• Limiting salt intake
• Restricting alcohol
• Avoiding grapefruit and grapefruit juice due to their effect on a group of immunosuppressive medications

After your bone marrow transplant, regular physical activity helps you control your weight, strengthen your bones, increase your endurance, strengthen your muscles and keep your heart healthy. As you recover, you can slowly increase your physical activity.

Taking steps to prevent cancer is even more important after your transplant. Don't smoke. Wear sunscreen when you're outside, and be sure to get recommended cancer screenings.

A bone marrow transplant can cure some diseases and put others into remission. Goals of a bone marrow transplant depend on your condition but usually include controlling or curing your disease, extending your life, and improving your quality of life.

Some people have few side effects and complications from a bone marrow transplant. Others may experience short- and long-term side effects and complications. It can be difficult to predict the severity of side effects and the success of the transplant.

It can be helpful to remember that there are many people who have transplants who also experienced some very difficult days during the transplant process. But, ultimately, they had successful transplants and have returned to typical activities with good quality of life.