Which symptom may indicate an adverse reaction to a blood transfusion?

Fever and chills are common symptoms that may indicate an adverse reaction to a blood transfusion, particularly a febrile non-hemolytic transfusion reaction. This type of reaction is typically due to the recipient’s immune response to white blood cells or donor platelets in the transfused blood product. The onset of fever, often accompanied by chills, can occur within a few hours of starting the transfusion and is a significant sign that the patient's body is reacting to the transfused blood.

In the context of blood transfusion reactions, other symptoms may also be present, such as headache, malaise, or allergic symptoms, but fever and chills are among the most well-recognized indicators of a potential transfusion reaction.

Other listed symptoms, such as weight gain, bradycardia, or nausea and vomiting, can occur in various medical situations but are not as specifically associated with blood transfusion reactions as fever and chills. For instance, weight gain can be related to fluid overload, bradycardia could be associated with other cardiovascular issues, and nausea and vomiting may arise from different causes unrelated to transfusion reactions. Thus, recognizing fever and chills as indicators is crucial for timely intervention and management of potential transfusion-related complications.