What is a common sign of an infection?

Redness and swelling are common signs of an infection due to the body's inflammatory response to pathogens. When an infection occurs, the immune system sends various cells to the affected area, resulting in increased blood flow. This process causes the affected tissue to become red and swollen as white blood cells and other chemicals work to combat the infection. The combination of heightened blood flow and immune activity increases the temperature and tenderness of the area, serving as visual indicators that something is wrong.

While dry skin, itching, and scabbing can indicate various skin conditions, they are not specific markers of infection. Dry skin often results from lack of moisture, itching can be related to allergies or irritants, and scabbing typically indicates healing from an injury rather than an active infection. Thus, the presence of redness and swelling is a clearer and more direct indication of an infection.