What does inflammation actually mean?

Acute inflammation is the immune system working correctly. When tissue is injured or infected, blood vessels dilate and become permeable, immune cells arrive, and the classic signs follow: redness, heat, swelling, and pain. That process contains the threat and initiates repair, and suppressing it entirely would be harmful, which is worth remembering given how the word is used commercially. It resolves once the job is finished.

The concern is chronic low-grade inflammation, a persistent activated state without an acute threat, associated in research with cardiovascular disease, type 2 diabetes, some cancers, and autoimmune conditions. The causal direction is not always clear, and inflammation is often as much a marker as a driver. Contributors with reasonable evidence include visceral fat, which is metabolically active and secretes inflammatory signals, smoking, chronic poor sleep, sustained psychological stress, periodontal disease, and dietary patterns high in ultra-processed food. Two cautions about the popular version of this topic. The anti-inflammatory diet industry substantially overstates what specific foods do, and while overall dietary patterns like the Mediterranean pattern have decent support, individual superfoods and supplements marketed for inflammation generally do not. And C-reactive protein testing, sometimes sold direct to consumers, is a nonspecific marker that rises with any infection and is difficult to interpret without clinical context.