Blood transfusions are relatively common medical procedures that are performed millions of times each year in U.S. hospitals and around the world. A blood transfusion might be necessary when a patient has received a major traumatic injury resulting in severe blood loss. Or, a blood transfusion could be required for certain planned surgeries that typically result in considerable blood loss. Planned operations that may require a blood transfusion include the following:

• C-section

• Open heart surgery

• Joint replacement

• Orthopaedics

• And many others

The reason a blood transfusion could be necessary after blood loss is because of the role blood plays in supplying oxygen to the body. The smaller the amount of blood in a patient's body, the less oxygen makes it to that patient's vital organs and tissues. Without enough oxygen, major organs such as the brain and heart will eventually shut down.

Although blood transfusions are relatively safe medical procedures that have a high rate of success with little or no complications, many patients opt for alternative medical procedures. Bloodless surgery is one such alternative. The field of bloodless medicine is actually a number of different techniques and procedures designed to increase the amount of oxygen in the blood and limit blood loss during surgery.

Some patients choose the bloodless route over a traditional blood transfusion for religious reasons. Others decide to have a bloodless surgery because of the risks that are involved with a blood transfusion. Although hospitals and healthcare systems do everything within their power to make blood transfusions as safe as possible, there is no guarantee that a blood transfusion will be a 100% safe procedure.

Below are 10 risks associated with blood transfusions that every patient should be aware of:

1.) Viruses and infectious diseases -

Even though blood donation organizations and blood banks have strict screening and testing procedures, there have been instances where patients have received contaminated blood from a transfusion. Viruses and diseases that can be transmitted through a blood transfusion include HIV, Hepatitis, West Nile Virus, and CJD (the human form of "mad cow disease").

2.) Allergic reaction -

When blood is donated, it is donated as whole blood. The whole blood is then separated into the various blood parts that might be needed in a transfusion (red and white cells, platelets, etc.). Sometimes the donor blood can contain other particles which might trigger an allergic reaction in the recipient. Allergic reactions during a transfusion can be mild to severe and require the transfusion to be stopped at the first sign.

3.) Lung injury -

In some cases, patients receiving a blood transfusion can experience lung damage. This can be caused by an immune reaction which attacks the recipient's lungs. Lung injuries present a serious blood transfusion risk - nearly 25% of these injuries prove fatal.

4.) Graft-versus-host disease (GVHD) -

Graft-versus-host disease (GVHD) is a serious condition where the new white blood cells attack the recipient's body. This condition typically only affects patients with weak immune systems and is often fatal.

5.) Acute immune hemolytic reaction -

An acute immune hemolytic reaction is a rare, but serious condition. This occurs when the recipient's body attacks the new red blood cells. This produces substances in the blood that can harm the kidneys. The transfusion should be stopped immediately at the first sign of an acute immune hemolytic reaction. The symptoms include dark urine, fever, chills, and back or chest pain.

6.) Delayed hemolytic reaction -

A delayed immune hemolytic reaction is similar to the acute condition; however, the delayed reaction is much slower. This kind of reaction is extremely dangerous because it can go unnoticed while the patient's red blood count drops.

7.) Fever -

When another person's blood enters the recipient's body, a fever is a normal and common immune response to the presence of the foreign white blood cells. Most fevers are mild and do not disrupt the transfusion.

8.) Too much iron -

In some cases, where a patient must receive large amounts of blood through multiple transfusions, too much iron can build up in the blood. An "iron overload" such as this can damage the liver and other vital organs.

9.) Fluid overload -

Patients who must receive multiple transfusions are at risk for fluid overload. Essentially the presence of too much fluid in the blood, fluid overload can result in a reduction in the amount of oxygen in the blood. Cardiac failure can result if the excess fluid isn't promptly drained.

10.) Human error / wrong blood type -

Blood transfusions are a medical operation and, as with any medical procedure, there is always the risk for human error. If a patient accidentally receives the wrong blood type during a transfusion, they could suffer mild to severe allergic reactions and other serious complications.