What are the three signs of infection?

The three signs of infection typically include pain, swelling, and redness. These signs are part of the body's inflammatory response to infection. When an area of the body becomes infected, the immune system responds by sending white blood cells to the site. This increases blood flow in the area, leading to swelling and redness. Pain can result from the pressure caused by the swelling and the release of inflammatory mediators.

The other options present symptoms that can be associated with various conditions, but they don't specifically encompass the classic signs of infection. For instance, fever, chills, and coughing may indicate a systemic infection or respiratory issue, while headache, diarrhea, and vomiting can be symptoms of gastrointestinal infections or other illnesses rather than the localized signs you would expect from most infections.