What are common signs and symptoms of infection?

Fever, redness, and swelling are classic signs of infection, making this option a clear indicator of the body's response to invading pathogens. Fever is the body’s systemic response to infection as it raises the temperature, creating an environment less favorable for pathogens. Redness and swelling occur at the site of infection due to increased blood flow and the accumulation of immune cells, which work to fight off the infection. These three symptoms are often interconnected, demonstrating the body's inflammatory response to pathogens and emphasizing the area in need of attention.

In contrast, while options like fatigue, cough, dizziness, or headache can occur with infections, they are not as definitive or specific as fever, redness, and swelling for diagnosing infection. Fatigue can be caused by numerous conditions, and while cough can indicate respiratory infection, it is not a universal sign of infection. Similarly, dizziness and headache can arise from various non-infectious sources. Loss of appetite, insomnia, and rash are also signs that can occur in diverse health scenarios and may not directly indicate an active infection.