Understanding Blood Transfusion as a Treatment for Anemia

It can restore your blood count to alleviate symptoms and prevent complications

Medically reviewed by Doru Paul, MD

Anemia is a low red blood cell (RBC) count or abnormal RBC function. Because RBCs deliver oxygen throughout the body, anemia affects the function and health of every organ and causes symptoms such as fatigue, light-headedness, and feeling cold.

Getting adequate nutrients through diet and enough rest are often sufficient to resolve anemia. However, a blood transfusion can be a lifesaving intervention for severe anemia, and this procedure might be part of ongoing therapy for certain blood disorders.

This article describes blood transfusions and what to expect if you need one for anemia.

<p>Suwinai Sukanant / 500px / Getty Images</p>

Suwinai Sukanant / 500px / Getty Images

What Are Blood Transfusions Exactly?

If you have a blood transfusion, you will receive blood that was donated by a healthy person.

During this procedure, the donated blood is introduced into your body through a vein. It takes about an hour to complete a blood transfusion, depending on how much donor blood you need to receive and the flow rate of the infusion.

How Does a Blood Transfusion Help Anemia?

A blood transfusion helps treat anemia by replacing RBCs to alleviate symptoms and prevent harmful health consequences. Anemia develops if you are unable to produce enough healthy RBCs due to disease or rapid bleeding. In severe cases, it can lead to loss of consciousness or permanent organ damage.

A blood transfusion can quickly replace RBCs that your body can’t replenish fast enough.

How Do You Know If a Blood Transfusion for Anemia Is Right for You?

A blood transfusion is a well-established procedure with known health indications and benefits. Generally, the decision to proceed with a blood transfusion is based on factors such as symptoms, cause of bleeding, and hemoglobin level.

Hemoglobin is a protein that binds to oxygen in RBCs. A blood test can measure hemoglobin concentration.

Generally, consideration for transfusion starts at levels below 7 to 8 grams hemoglobin per deciliter of blood (g/dL). However, the exact criteria and protocol will depend on the underlying medical condition, the person's symptoms, and/or the procedure being done (such as surgery).

An example of when you might need a transfusion is having lost a significant amount of blood due to a major injury or as a result of extensive gastrointestinal bleeding. It could be very difficult for your body to catch up with the RBC loss. In this situation, you could experience life-threatening consequences of anemia, and a blood transfusion could be necessary for your survival.

Sometimes, a blood transfusion is planned as part of the treatment during a major surgery when substantial blood loss is anticipated. When it's planned in advance, you might be able to have an autologous blood transfusion—which is "banking" your own blood before your procedure so you can receive it intravenously to replace the blood that's lost during your operation.

Certain health conditions, such as bone marrow disorders, intestinal bleeding, or cancer, may lead to a slow onset of anemia—potentially causing the need for a blood transfusion.

Types of Transfusions for Anemia

Blood transfusions for anemia include RBCs, but in certain circumstances, blood transfusions may specifically include platelets (cells that assist in blood-clotting) or other blood components, depending on the underlying condition that’s being treated.

What Happens During a Blood Transfusion for Anemia?

Before you receive a planned blood transfusion, you would have your blood typed and crossmatched so you receive blood from a matching donor and no concerning mismatch is detected.

Blood types are determined based on markers (antigens) on the surface of red blood cells. The major blood types are O, A, B, and AB, and each is designated as Rh positive or Rh negative. If receiving mismatched blood, immune reactions can occur, including some that are severe and life-threatening.

If you need blood in an emergency and typing or crossmatching is not possible, you will receive type O negative blood. This type is considered a universal donor because it does not have the antigens that could trigger a major incompatibility reaction.

The Procedure

During your blood transfusion, an intravenous needle injected into your vein, and a thin plastic tube carries the donor blood from a sterile bag into your vein. Throughout your blood transfusion, you may also have your blood pressure checked, your pulse rate measured, and your oxygen saturation measured.

Medical staff will frequently check on you to see if you are having any side effects and ensure that the infusion rate is adequate.

What Happens After a Blood Transfusion for Anemia?

After your blood transfusion is complete, your healthcare providers will remove the needle from your vein. After making sure that you are not bleeding from the vein, they will apply pressure for a few minutes and cover the puncture site with a bandage.

If you are a hospital inpatient (staying overnight), you will continue with your other treatment. If you receive a blood transfusion as an outpatient, you will have your blood pressure and other vital signs measured, and then you will be able to go home after it is clear that you are stable.

After having a blood transfusion, it may take a few days for you to recover, especially if a large quantity of blood was replaced.


Sometimes people need repeated blood transfusions due to an underlying medical condition that causes recurrent anemia. Intermittent surveillance with blood tests can identify anemia, and will be used to determine the need for repeated blood transfusion.

What Are the Potential Risks and Complications of a Blood Transfusion for Anemia?

A few risks and complications are associated with blood transfusion. The most serious risk is a mismatched donor and recipient, which will cause a severe immune reaction. This reaction is very rare due to the great care taken in typing, crossmatching, and identifying the blood unit and recipient before transfusion.

Other risks of blood transfusion are also very low due to the screening of blood donors, testing of donated blood, and medical stabilization of recipients.

Risks may include:

  • Febrile nonhemolytic transfusion reaction (FNHTR): This is the most common reaction reported after a transfusion. In this reaction, the recipient feels chills and/or fever in the four hours after transfusion. It is a mild reaction in most cases, but a severe reaction is possible.

  • Allergic reaction: An allergen in the transfused blood interacts with preformed antibodies in the recipient's blood. This may produce skin or mucous membrane irritation, or the person may develop a severe allergic reaction that can include difficulty breathing (anaphylaxis).

  • Transmission of a contagious infection: This risk is minimized with the screening of donors and testing of the donated blood for infections, such as hepatitis and human immunodeficiency virus (HIV).

  • Blood pressure instability: The risk can be minimized with careful surveillance of the recipient before, during, and after the blood transfusion.

  • Hemochromatosis: This condition means iron overload. Repeated blood transfusions can increase the risk of this complication. Carefully scheduling blood transfusions in order to avoid iron overload can help prevent hemochromatosis from developing.

Alternatives to Blood Transfusion for Anemia

Blood transfusion is one treatment for severe anemia. Depending on the underlying condition and the severity of anemia, sometimes other treatments are preferred instead, such as:

  • Iron supplementation: Iron deficiency is a common cause of anemia. If the blood count is not dangerously low, iron deficiency is treated with dietary changes and iron supplementation.

  • Vitamin B12 supplementation: Vitamin B12 is essential for RBC formation. Sometimes, supplementation with this vitamin is necessary to treat anemia associated with low vitamin B12 levels.

  • Erythropoietin: Kidney failure is another cause of anemia, The treatment of anemia caused by kidney failure can include erythropoietin, a hormone produced in the kidney that stimulates RBC production.

Learn More: How Anemia Is Treated

What’s the Outlook for People With Anemia Who Have a Blood Transfusion?

Generally, blood transfusion is very effective for treating severe anemia. This therapy is beneficial for rapidly progressive and severe anemia, as well as for anemia that develops over a long period of time or recurs due to chronic diseases. The risk of complications is fairly low.


If you have a medical condition that causes chronic anemia, or if you’ve had an episode of acute anemia, you may have had a blood transfusion or a blood transfusion might have been considered as a potential therapy.

Precautionary measures help prevent the most common side effects, making complications fairly rare. Living with anemia can be challenging and interfere with quality of life. However, it is possible to live a healthy life and lower the chances of serious consequences. If you are at risk for recurrent anemia, a blood transfusion may be part of your treatment plan.

Read the original article on Verywell Health.