What are the primary characteristics of inflammation?

The primary characteristics of inflammation are redness, heat, pain, and swelling. Inflammation is the body's natural response to injury or infection and serves several critical functions in the healing process.

Redness and heat occur due to increased blood flow to the affected area, which brings with it immune cells necessary for fighting infection and healing damaged tissue. Pain is a result of the release of chemicals that sensitize nerves in the affected area, serving to protect the injured site by prompting the individual to limit movement. Swelling is caused by the accumulation of fluid and white blood cells in the tissues, aimed at isolating harmful agents and facilitating repair.

While fever and chills can sometimes accompany inflammation, they are not defining characteristics of the inflammatory response itself. Similarly, rashes and discoloration may occur due to various skin conditions and are not direct indicators of inflammation, nor are weakness and fatigue which can arise from many different factors apart from inflammation. The specific combination of redness, heat, pain, and swelling clearly emphasizes a localized inflammatory response, making it the most accurate choice among the options given.