As we saw last week, acute inflammation is the body's natural immune reaction to heal injuries, combat pathogens, and to protect itself. This week, we'll look at what chronic inflammation is, some of its causes, and how it affects the body.
Chronic inflammation means swelling that continues for an extended period of time. Tendonitis is an example of chronic inflammation. A tendon attaches muscle to bone. Overuse with repetitive motion, or injury like a strain or tear, can cause the tendon to swell. When that swelling persists (even though the injury itself has healed), the doctor may diagnose tendonitis. In such a case, the swelling may not be outwardly visible, but there is heat, pain, and limited range of motion.
The example above tells us that overuse of a body part can be one cause of chronic inflammation. There are several more potential causes -- some that are understood, some partially understood, and some that have not yet been discovered. Genetics, aging, injury, infection, auto-immune disease, exposure to chemicals/pollution, smoking, poor diet, obesity, excessive use of alcohol, and chronic stress can all be contributing factors to and/or direct causes of chronic inflammation. However, two people could experience the exact same contributing factors, but only one of them develops chronic inflammation. Scientists are still trying to understand how and why that happens.
What we do know more about is the effect chronic inflammation has on the body. Because chronic inflammation can last for years, it can harm rather than heal the body. If it's in one or more joints, it can cause further damage to soft tissue (i.e. cartilage). Inflammation that continues for many years, will eventually cause cell damage, scarring, and possibly DNA damage. If left unchecked, it can cause diseases like diabetes, asthma, heart disease, OA, RA, atherosclerosis, some types of cancer, autoimmune diseases, Crohn's, UC, Psoriasis, Nephritis, Myalgias, MS, FM, Colitis, and neurodegenerative diseases (example: Alzheimer's Disease). Many of these diseases then cause more inflammation, and the cycle starts to spiral out of control. The list goes on, but you're starting to see that chronic inflammation plays a role in the development of many of the diseases we encounter as we age.
This list looks scary -- and it is. The good news is that there are steps we can take to reduce chronic inflammation and hopefully, avoid its ravages on our bodies. We'll look at these steps in two weeks. Before that, I want to show in more detail exactly how chronic inflammation impacts our bodies. So, next week, I'm going to focus on one of the above diseases from the list - Alzheimer's Disease - and show how chronic inflammation is a key contributing factor in the onset and continuing degeneration of the brain.
1. PPT Health, Diseases Caused by Chronic Inflammation, 2019, https://www.ppt-health.com/inflammation-relief/diseases-caused-by-chronic-inflammation/, Accessed May 5 - 7, 2019
2. Santos-Longhurst, Adrienne, Understanding and Managing Chronic Inflammation, Healthline, July 27, 2018,
https://www.healthline.com/health/chronic-inflammation, Accessed May 5 - 7, 2019
3. Nordqvist, Christian, Everything you need to know about inflammation, Medical News Today, Last updated Nov. 24, 2017,
Accessed May 5 - 7, 2019