Stem cell transplant

A stem cell transplant replaces damaged bone marrow with healthy blood-forming cells after high-dose treatment.

Rosa: Hi, I'm Rosa. A stem cell transplant is a big journey, and it helps to know what's ahead. Let's go through it step by step.

A stem cell transplant, also called a bone marrow transplant, replaces blood-forming cells. These cells live in the bone marrow and make red blood cells, white blood cells, and platelets. Transplants are used mostly for blood cancers like leukemia, lymphoma, and multiple myeloma, and for some other blood disorders.

There are two main kinds. In an autologous transplant, your own stem cells are collected and stored, then given back after high-dose chemo. This lets you get stronger treatment than your marrow could otherwise handle. In an allogeneic transplant, the cells come from a donor, such as a brother or sister, an unrelated matched donor, a half-matched family member, or cord blood. The donor's immune cells can also attack the cancer, which is called the graft-versus-tumor effect.

First, stem cells are collected from the blood after shots that move them out of the marrow. This is done with a machine, much like donating blood. Next comes conditioning: chemo, and sometimes radiation, to clear out the marrow and the cancer. Then the stem cells are given through a vein, a bit like a blood transfusion. The new cells travel to the bone marrow and start making blood cells. This is called engraftment and usually takes about 2 to 4 weeks.

Most people stay in the hospital or come to the clinic daily for several weeks. Common side effects during this time include tiredness, nausea, mouth sores, diarrhea, low appetite, and very low blood counts. You may need blood and platelet transfusions. Recovery takes months, and with a donor transplant it can take a year or longer for the immune system to fully recover.

After an allogeneic transplant, a serious side effect is graft-versus-host disease (GVHD). This happens when donor immune cells attack healthy tissue. It can affect the skin, gut, liver, eyes, mouth, and lungs. You will take medicines to prevent it. Infections are another major risk, so you will take medicines to prevent them and will need to get your childhood vaccines again later.

Call your transplant team right away for fever of 100.4°F (38°C) or higher, chills, new rash, diarrhea, belly pain, yellow skin or eyes, cough or shortness of breath, bleeding, or not being able to eat or drink. Do not wait until your next visit. If it feels very bad, call 911.

Caregiver plan

Most transplant centers require a caregiver to be with you around the clock for weeks after transplant. Plan this early and think about backup helpers.

Finding a donor

If you need a donor, the team will test family members first and search national registries. Thanks to new methods, half-matched family donors are now a common option.

Preventing infection

Wash hands often, avoid crowds and sick people early on, and follow food safety rules your team gives you. Take all preventive medicines exactly as directed.

Life after transplant

Recovery is gradual. Expect regular clinic visits, blood tests, and changes in medicines. You will get a new vaccine schedule. Ask about late effects to watch for over the years.

Questions to ask

Which type of transplant do you recommend and why? How long will I be in the hospital or need to stay nearby? What are my main risks? When can I go back to work or school?

Myth: A stem cell transplant is surgery

Fact: There is no operation. The stem cells are given through a vein, much like a blood transfusion.

Myth: Donating stem cells is very painful and risky

Fact: Most donors give cells from the blood with a machine, after a few days of shots. Donors may feel achy or tired for a short time, and serious problems are rare.

Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.