Marlene Cimons in The Washington Post:
Most of us think of inflammation as the redness and swelling that follow a wound, infection or injury, such as an ankle sprain, or from overdoing a sport, “tennis elbow,” for example. This is “acute” inflammation, a beneficial immune system response that encourages healing, and usually disappears once the injury improves.But chronic inflammation is less obvious and often more insidious.
Chronic inflammation begins without an apparent cause — and doesn’t stop. The immune system becomes activated, but the inflammatory response isn’t intermittent, as it is during an acute injury or infection. Rather, it stays on all the time at a low level. Experts think this may be the result of an infection that doesn’t resolve, an abnormal immune reaction or such lifestyle factors as obesity, poor sleep or exposure to environmental toxins. Over time, the condition can, among other things, damage DNA and lead to heart disease, cancer and other serious disorders.
More here.