What are the cardinal signs of inflammation?

The cardinal signs of inflammation are redness, heat, swelling, pain, and loss of function. These signs reflect the body's physiological response to injury or infection.

Redness is caused by the increased blood flow to the affected area, which brings immune cells and nutrients essential for healing. Heat also results from increased blood flow and the metabolic activity associated with the immune response. Swelling occurs due to the accumulation of fluid and immune cells in the tissues, a process known as edema. Pain is often a consequence of the release of various chemical mediators that stimulate nerve endings and signal injury, while loss of function can arise as a protective mechanism to limit movement and further injury to the affected area.

The other options mention some symptoms that can occur during inflammation but do not encapsulate all the classic signs. For example, while weakness and fatigue can accompany an inflammatory response, they are not considered cardinal signs. Itching can occur with inflammation but is not universally present and does not reflect the direct process of inflammation as classically defined. Bloating is also not a cardinal sign and may be associated with different physiological processes or conditions, rather than specifically with the inflammatory process.