Chronic Low-Grade Inflammation

Chronic low-grade inflammation is a persistent state of relatively modest inflammatory activity that lasts much longer than a normal acute inflammatory response. It can involve sustained production of inflammatory mediators and altered immune-cell activity without the dramatic local signs that often accompany acute infection or injury. The term is commonly used in research on aging, obesity, metabolic disease, and other chronic conditions .¹

Unlike acute inflammation, which is usually a rapid and self-limited response to a clear threat, chronic low-grade inflammation can persist when inflammatory triggers remain, tissue stress continues, or normal resolution processes are incomplete. Changes may be detectable through patterns of circulating markers such as C-reactive protein or inflammatory cytokines, but no single laboratory value universally defines the state in every context .¹

The phrase describes an inflammatory pattern, not a diagnosis by itself. Association with a chronic disease does not prove that low-grade inflammation is the sole cause of that disease, and the relevant pathways differ between conditions. It is also distinct from overt chronic inflammatory diseases in which inflammation may be more pronounced or tissue-specific. The concept is therefore useful for describing sustained, relatively modest inflammatory activity without implying a single diagnosis or causal pathway .¹