Anyone who has ever sprained their ankle, cut themselves while chopping vegetables, or been stung by a bee has seen the effects of inflammation firsthand. The pain, redness, swelling, and heat that it produces is the body's defense mechanism to fight off infectious agents like bacteria and repair tissue damage. Less obvious but similar in process, is the inflammation that results from an infection like a cold, the flu, or COVID-19.
Acute vs. chronic inflammation
Injuries and infections produce acute inflammation, the body's rapid response mechanism that aims to rid itself of the dangerous invader and return it to a state of balance. A release of warning chemicals sounds the alarm, which draws an army of white blood cells to the site of injury. Some of these cells neutralize the invaders, while others clean up the damage that results from the battle. Acute inflammation typically resolves quickly, within a period of hours to days.
Chronic inflammation can begin via the same process, with the body trying to rid itself of what the immune system interprets as foreign adversaries. But this can become a persistent state, even if the perceived threat isn't truly harmful to one's health. In autoimmune disorders like rheumatoid arthritis, lupus, type 1 diabetes, ulcerative colitis, and multiple sclerosis, the body mistakenly reacts to its own tissues as if they were foreign, and produces damaging inflammation against them.
This chronic kind of low-grade inflammation may continually simmer under the surface. An unhealthy lifestyle that includes smoking, a poor diet, alcohol consumption, sedentary behavior, stress, and weight gain can cause this type of persistent inflammation.