Your surgeon will be very careful during surgery to limit the amount of blood you lose. But blood may continue to ooze from tissues that were cut, even after the operation is over. To replace this blood, you may be given a blood transfusion. This is a safe and common procedure, during which you receive blood through an intravenous (IV) line placed in one of your blood vessels.
Several sources of blood are described here.
Blood From the Public (Volunteer Blood Donation)
The most common source of blood given during or after surgery is from volunteers in the general public. This kind of donation is called homologous blood donation. Your blood will be tested to make sure you receive the correct type of donor blood.
Many communities have a blood bank where healthy people can donate blood. This blood is tested to see if it matches yours.
You may have read about the danger of becoming infected with hepatitis, HIV, or other viruses after a blood transfusion. Blood transfusions are not 100% safe. But the current blood supply is thought to be safer now than ever. Donated blood is tested for many different infections, and the tests are very accurate. Also, blood centers keep a list of unsafe donors, so the risk of infection from blood transfusions is low.
Donors answer a detailed list of questions about their health before they are allowed to donate. These questions include risk factors for infections that can be passed through their blood, such as sexual habits, drug use, and current and past travel history.
Directed Donor Blood From a Family Member or Friend
This method involves a family member or friend donating blood before your surgery. This blood is then set aside and held only for your use.
Blood from these donors must be collected at least a few weeks before it is needed. The blood is tested to see if it matches yours and is also screened for infection.
Most of the time, you need to arrange with your hospital or local blood bank before your surgery to have directed donor blood.
It is important to note that there is no evidence that receiving blood from family members or friends is safer than receiving blood from the general public.
Autologous Blood Donation (Your Own Blood)
Although blood donated by the general public and used for most people is thought to be very safe, some people choose to use a method called autologous blood donation. Autologous blood is blood donated by you, which you later receive if you need a transfusion during or after surgery.
- You can have blood taken from 6 weeks to 5 days before your surgery.
- Your blood is stored and is good for a few weeks from the day it is collected.
- If your blood is not used during or after surgery, it is thrown away.
If you wish to donate your own blood, you must make arrangements yourself. Your hospital may be set up to receive these donations and store the blood. Otherwise, your local blood bank may handle this process. Most of the time, you will need to pay for this process.
Problems can arise with autologous blood donation.
- Donating this blood can make you anemic, or have a lower blood count, before your surgery. As a result, it is still possible that you will need to receive a blood transfusion with blood donated by the general public. In this case, your provider may suggest that you do not donate your own blood too close to your surgery date so that you have time to recover before surgery.
- In rare cases, a mistake by the blood center or the hospital can result in you receiving the wrong unit of blood. If this happens, you may have a reaction to the blood you receive.
To help your body make more blood cells, your provider may ask you to take extra vitamins and minerals, including:
- Iron tablets
- Folic acid
- Vitamin C
You may also get a medicine by injection to boost your blood count before surgery.
Hsu YMS, Ness PM, Cushing MM. Principles of red blood cell transfusion. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 111.
Miller RD. Blood therapy. In: Pardo MC, Miller RD, eds. Basics of Anesthesia. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 24.
U.S. Food and Drug Administration website. Blood and blood products. www.fda.gov/vaccines-blood-biologics/blood-blood-products. Updated July 12, 2021. Accessed November 29, 2021.
Review Date 7/28/2021
Updated by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.