Acute Inflammation

Acute inflammation is the rapid, short-term response of vascularized tissue and the innate immune system to infection, injury, or other harmful stimuli. It begins within minutes to hours and is designed to contain or remove the trigger, clear damaged material, and create conditions for tissue repair .¹

A typical acute response involves widening of local blood vessels, increased vascular permeability, movement of plasma proteins into tissue, and recruitment of white blood cells. Neutrophils are often prominent early, while monocytes and macrophages contribute to later cleanup and coordination. Chemical mediators such as histamine, prostaglandins, complement components, and cytokines help organize these changes .¹

Acute inflammation is different from infection. Microorganisms can trigger inflammation, but sterile tissue damage can do so as well. It is also distinct from chronic inflammation, which persists and often involves different mixtures of immune cells, tissue remodeling, and ongoing injury. Acute inflammation normally resolves when the initiating stimulus is controlled, although an intense response can itself damage tissue or progress to a chronic state if the trigger remains .¹