Blood transfusions and growth factor shots

Why you might need red cells, platelets, or shots that help your body make blood cells.

Rosa: Hi, I'm Rosa. Treatment can lower your blood counts. Let me explain how transfusions and growth factor shots help, and what to expect.

Cancer and its treatment can lower your blood counts. Red blood cells carry oxygen. Platelets help your blood clot. White blood cells fight infection. When counts get too low, your care team may give you blood products. Or they may give medicines that help your body make more.

A red blood cell transfusion can help if anemia causes symptoms. These include feeling very tired, short of breath, dizzy, or having a fast heartbeat. Your team looks at your symptoms and your blood test results to decide. Many people feel better within a day or two.

You may get a platelet transfusion if your platelets are very low or you are bleeding. It may also be given before a procedure. Platelets do not last long in the body, so some people need them often.

A transfusion is given through an IV or port, usually in a clinic or hospital. It often takes one to a few hours. Before your first one, a blood sample is taken to match your blood type. Staff check your name and blood type more than once to keep you safe.

The US blood supply is carefully tested. Blood is screened for HIV, hepatitis, and other infections. The chance of catching an infection from a transfusion is very, very small.

Growth factor shots help your bone marrow make blood cells. White cell growth factor shots lower the chance of infection after some chemotherapy. They may be given the day after chemo or through a small device stuck to your skin. Red cell growth factor shots are used less often and only in certain situations. Your team will explain the benefits and risks for you.

During a transfusion

Nurses check your temperature, pulse, and blood pressure. Tell them right away if you feel chills, fever, itching, a rash, back pain, chest tightness, or trouble breathing.

After you go home

Most reactions happen during the transfusion. In the next few days, call your care team for a fever, dark urine, or yellow skin or eyes. Also call for trouble breathing.

Special blood for some people

People who had a stem cell transplant, Hodgkin lymphoma, or certain treatments may need irradiated blood. This prevents a rare but serious reaction. Ask if this applies to you and tell any new hospital.

Many transfusions over time

Red blood cells contain iron. After many transfusions, extra iron can build up in the body. Your team can check for this with a blood test and treat it if needed.

Growth factor shot side effects

Bone pain is common, often in the back, hips, or legs. Ask your team what you can take for it. Call right away for pain in the upper left belly or shoulder, or trouble breathing.

If you have beliefs about blood

Tell your care team early if you do not accept blood products for religious or personal reasons. There are other options and plans they can make with you.

Myth: a transfusion means things are getting worse

Fact: transfusions are a common, routine part of supportive care. Many people need one or more during treatment.

• Ask what your blood counts are and what numbers your team watches.
• Learn the signs of low red cells (tiredness, shortness of breath) and low platelets (bruising, bleeding).
• Ask if you need special blood products, and keep a note of it.
• Plan for a ride and something to do on transfusion days.

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.