After a cut or infection the immune system launches acute inflammation at once, and when the threat clears, pro-resolving mediators actively shut it down.Cut, infection, sprain — the immune system fires immediately: vasodilation (red, hot), increased permeability (swelling), neutrophil/macrophage influx. This is defensive and self-limiting: once the threat clears, pro-resolving mediators (lipoxins, resolvins) actively shut it down.
2 · Chronic inflammation · smoldering fire
When the trigger persists, inflammation does not shut off: macrophages keep releasing inflammatory cytokines, and without redness or pain, tissue is slowly eroded.When the trigger persists — visceral fat, periodontal disease, chronic infection, autoimmunity, chronic psychological stress — inflammation doesn't shut off. Macrophages continuously release , , IL-1β, . No redness/swelling/pain, but tissue is slowly eroded. This is pathological.
3 · Major drivers
The main sources of chronic inflammation are visceral fat, diet, a leaky gut barrier, poor sleep and stress, and environmental toxins.① Visceral fat: adipose macrophages are the largest chronic inflammation source. ② Diet: ultra-processed foods, trans fats, excess fructose, excess alcohol. ③ Gut barrier: leaky gut lets LPS enter blood, chronically activating TLR4. ④ Poor sleep/stress: cortisol dysregulation. ⑤ Environmental toxins: PM2.5, smoking.
4 · Diseases · the common soil
Chronic low-grade inflammation is the common soil of nearly all modern chronic diseases, from atherosclerosis and type 2 diabetes to depression.Chronic low-grade inflammation is the common soil of nearly all modern chronic diseases: atherosclerosis (/ predict ), type 2 diabetes (inflammatory basis of insulin resistance), , certain cancers, Alzheimer's (neuroinflammation), autoimmune diseases, depression (cytokine hypothesis).
Mechanism
Acute vs chronic inflammation · bright fire vs smolder