"Excessive inflammation" means that there is too much swelling, redness, and pain in a certain part of the body, usually as a response to an injury or infection. Full definition
The short answer: when the immune system gets out of control and causes excessive inflammation, or when it triggers the inflammatory response when it's not necessary. (mindbodygreen.com)
As with heart disease, risk of type 2 diabetes increases with excessive inflammation and oxidative stress. (livescience.com)
Once you identify the source of inflammation in your body, it becomes easier to prevent excessive inflammation with treatment and lifestyle changes. (wallerwellness.com)