Blood transfusions work to replace blood that is lost due to injury, surgery, or to treat medical conditions. The type of blood transfusion given depends on the reason for requiring one.

This article will outline what a blood transfusion is, when they are necessary, and what to expect during the procedure.

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A person may require a blood transfusion if they have anemia, hemophilia, or cancer.

A blood transfusion is a procedure that restores blood to the body.

A healthcare professional will pass blood through a rubber tube into a vein using a needle or thin tube.

The sections below will cover the different types of blood transfusion procedures available, as well as the different types of blood.

Types of blood transfusions

According to the American Red Cross, there are four common types of blood transfusions:

  • Red blood cell transfusions: A person may receive a red blood cell transfusion if they have experienced blood loss, if they have anemia (such as iron deficiency anemia), or if they have a blood disorder.
  • Platelet transfusions: A platelet transfusion can help those who have lower platelet counts, such as from chemotherapy or a platelet disorder.
  • Plasma transfusions: Plasma contains proteins important for health. A person may receive a plasma transfusion if they have experienced severe burns, infections, or liver failure.
  • Whole blood transfusion: A person may receive a whole blood transfusion if they have experienced a severe traumatic hemorrhage and require red blood cells, white blood cells, and platelets.

Before a blood transfusion, a healthcare professional will remove the white blood cells from the blood. This is because they can carry viruses.

That said, they may transfuse white blood cells called granulocytes to help a person recover from an infection that has not responded to antibiotics. Healthcare professionals can collect granulocytes using a process called apheresis.

Blood types

It is important that a healthcare professional uses the correct blood type during a blood transfusion. Otherwise, the body might reject the new blood, which can have severe consequences.

There are four types of blood:

  • A
  • B
  • AB
  • O

Each blood type can be positive or negative.

Blood type O is compatible with all other blood types. People with blood type O are universal donors.

If someone is in a critical condition and bleeding heavily, a doctor may use universal blood donor blood.

Blood transfusions are necessary when the body lacks enough blood to function properly. For example, a person may need a blood transfusion if they have sustained a severe injury or if they have lost blood during surgery.

Some people need blood transfusions for certain conditions and disorders, including:

  • Anemia: This occurs when a person’s blood does not have enough red blood cells. It can develop for a number of reasons, such as if a person does not have enough iron in their body. This is known as iron deficiency anemia.
  • Hemophilia: This is a bleeding disorder wherein the blood is unable to clot properly.
  • Cancer: This occurs when cells in the body divide and spread to the surrounding tissues.
  • Sickle cell disease: This is a group of red blood cell disorders that change the shape of red blood cells.
  • Kidney disease: This occurs when the kidneys are damaged.
  • Liver disease: This occurs when the liver stops functioning properly.

Most blood transfusions take place in a hospital or at a clinic. However, visiting nurses may be able to perform blood transfusions at home. Before this, a doctor will need to perform a blood test to determine a person’s blood type.

During a blood transfusion, a healthcare professional will place a small needle into the vein, usually in the arm or hand. The blood then moves from a bag, through a rubber tube, and into the person’s vein through the needle.

They will carefully monitor vital signs throughout the procedure. It can take up to 4 hours to complete a blood transfusion.

Recovery time may depend on the reason for the blood transfusion. However, a person can be discharged less than 24 hours after the procedure.

A person may feel an ache in the hand or arm after a transfusion. There may also be some bruising at the site.

There may be a very small risk of a delayed reaction to the transfusion. Although this does not typically cause problems, a person should consult a doctor if they feel unwell and have unexpected symptoms, such as nausea, swelling, jaundice, or an itchy rash.

It is important to let a doctor know about any symptoms that might signal a reaction, such as nausea or difficulty breathing.

To discover more evidence-based information and resources for donating blood, visit our dedicated hub.

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Blood transfusions are very safe. Strict procedures exist to ensure that the testing, handling, and storage of donated blood is as safe as possible.

However, it is possible for a person’s body to react to the new blood. Such reactions can be either mild or severe.

Some reactions occur immediately, while others can take several days to appear. Examples include:


Allergic reactions are common. In fact, according to the Centers for Disease Control and Prevention (CDC), allergic reactions make up over 50% of reported reactions to blood transfusions.

Antihistamine medications can help treat allergic reactions.


A person may experience a fever following a blood transfusion.

Although this is not serious, if they also experience chest pain or nausea, they should let a doctor know as soon as possible.

Hemolytic reaction

This can occur when the blood types are not compatible, causing the immune system to attack the new blood cells.

This is a serious reaction, but it is very rare.

Symptoms may include:

  • lower back pain
  • chest pain
  • dark urine
  • nausea
  • fever

Transmission of infections

In very rare cases, donated blood can contain bacteria, viruses, or parasites that may cause infections such as HIV or hepatitis B or C.

However, according to the CDC, experts test every blood donation for these contaminants. It is therefore very rare for a person to contract an infection from a blood transfusion.

In fact, according to the American Red Cross, the chance of a person contracting hepatitis B is 1 in 300,000, and the likelihood of contracting hepatitis C is 1 in 1.5 million.

The chances of getting HIV from a blood transfusion in the United States is less than 1 in 1 million.

A blood transfusion is a safe procedure that replaces blood lost to injury or surgery. It can also help treat certain medical conditions.

Blood transfusions can be lifesaving, but they can cause some mild side effects.

Although infections are very rare, it is possible for the body to react to the new blood. In most cases, however, these reactions are mild.