What can agglutination lead to if blood types are mixed improperly?

Agglutination occurs when antibodies in the blood bind to specific antigens on the surface of red blood cells. If blood types are mixed improperly—such as receiving a transfusion of blood with incompatible antigens—this leads to an immune response where the body attacks the transfused cells. As a result, a blood transfusion reaction can occur.

This medical complication is characterized by the agglutination of the red blood cells, which can cause clumping and ultimately block blood vessels. The reaction can lead to severe outcomes, such as organ damage, kidney failure, and even death if not treated promptly. The consequences are serious enough that blood type compatibility is a crucial factor in blood transfusions to prevent such risks.

While increased oxygen levels and decreased blood pressure may occur in various medical contexts, they are not direct results of agglutination from improper blood mixing. Blood clots may be a consequence of other types of medical conditions but do not specifically describe the reaction due to agglutination in transfusions. Therefore, the most accurate answer relates to the serious complications arising from an immune response to incompatible blood types, making blood transfusion reactions the correct and most relevant choice.