What is a common symptom of bacterial infections?

Fever and inflammation are common symptomatic responses to bacterial infections due to the body's immune response. When the body detects an invading pathogen, such as bacteria, it activates the immune system to fight the infection. This immune response includes the release of pyrogens, substances that induce fever, as well as inflammatory mediators that lead to inflammation.

Fever serves to create an environment less favorable for bacterial growth and enhances the effectiveness of the immune response. Inflammation involves redness, swelling, heat, and pain at the infected site, which helps to isolate and eradicate the pathogen. These symptoms are vital indicators of an infection and are commonly observed in patients suffering from bacterial diseases.

While the other options may have some relevance in different contexts, they do not typically reflect the body's reaction to bacterial infections. For instance, increased energy and improved appetite are more associated with health rather than illness, and weight loss could be a consequence of chronic infection but is not a direct response to the infection itself.