Inflammation is highly involved in numerous ailments and disease processes including heart disease, cancer, diabetes, ulcers, asthma, mood issues, tendonitis, arthritis, Alzheimer’s, strokes, autoimmune diseases, inflammatory bowel disease, and the list goes on and on.
But What IS inflammation? What is happening in the body at the tissue and cellular level when we have inflammatory reactions?
Inflammation is categorized as Acute or Chronic.
Acute Inflammation
Acute inflammation is the normal, protective, rapid response of the immune system to infection or tissue damage. It typically develops within minutes to hours and lasts from hours to days. Like strep throat….ouch!
Acute inflammation has 5 cardinal signs:
- Redness – from increased blood flow to the infected or injured tissue
- Heat – from increased blood flow and increased metabolic and chemical reactions
- Swelling – also called edema, which is caused by the leaking of blood plasma containing nutrients and immune cells into the tissue
- Pain – caused by stimulation of pain neurons from tissue injury or from cytokines made by damaged cells and immune cells. Pain is important because it forces us to protect the injured body part so it can heal.
- Loss of function – because of tissue being infected or damaged
Acute inflammation occurs in a series of steps:
- Tissue damage occurs and/or infectious organisms like bacteria invade the tissue
- Immune cells recognize damaged cells and infectious organisms by chemical messengers called chemokines or cytokines and attract more immune cells to the damaged area
- Immune cells that are the first responders include neutrophils and macrophages that engulf dead cells, engulf and and kill microorganisms, and produce more cytokines to attract more immune cells. Sometimes pus develops which is composed primarily of bacteria and neutrophils. Cytokines like histamine and prostaglandins cause blood vessels to become leaky to let fluid and immune cells get into the tissue area.
- Neutrophils release chemicals that kills cells somewhat randomly. It is a kamikaze kind of way of rapidly killing a lot of microorganisms but it also kills some normal healthy cells. Some of the cytokines released stimulate new cell division to replace the cells that were destroyed.
- The infectious organisms and dead cells are removed, new cells grow, the tissue is repaired, sometimes a scar may form, and the immune response is down-regulated
Chronic Inflammation
Chronic inflammation is a longer-lasting, slower but progressive immune response that can last for weeks or months, and possibly years. During chronic inflammation the immune system continuously releases cytokines that attract immune cells that continually damage normal tissue (in an attempt to get rid of the offending substance and heal the tissue). The immune system means well but when it is continuously over-stimulated then it just causes more and more damage to healthy tissue.
Immune cells release signals that stimulate cell division in order to repair the tissue, but when this is continuous, it causes excess cell division and is why chronic inflammation is associated with cancer cell growth.
Chronic inflammation is not always associated with pain depending on the location. For example, we cannot feel the inflammatory process of atherosclerosis in our blood vessels, so this can go on for years and even decades without being aware of it.
A few characteristics of chronic inflammation:
- The immune cells that predominate in chronic inflammation are macrophages and lymphocytes, rather than the neutrophils that predominate in acute inflammation
- Tissue destruction can become extensive
- Attempts at tissue repair result in excess connective tissue rather than cells, so scar tissue can form, including inside the body, this is called fibrosis
- Increased formation of blood vessels, called angiogenesis, is a further attempt by the body to repair the tissue. Angiogenesis is also associated with cancer cell growth
Causes of chronic inflammation
- Persistent infections – sometimes it is difficult for our immune system to completely get rid of a pathogen because some organism have evolved creative mechanisms for evading our immune system. Some examples include mycobacterium tuberculosis, HIV, herpes, cytomegalovirus, parasites, yeast infections, lyme disease or Helicobacter pylori (linked with ulcers).
- Hypersensitivity reactions – when the immune system targets a harmless substance like peanuts or cat fur and reacts as though it were an infection
- Autoimmune diseases –when the immune system targets one of your own cell types and reacts as though it were an infection, such as Rheumatoid arthritis, lupus, Crohn’s, type 1 diabetes, psoriasis, or Grave’s. There are over 100 autoimmune diseases. Here is a complete list if you are interested https://www.aarda.org/diseaselist/
- Prolonged exposure to toxic agents – this category includes toxins you consume, breathe, or absorb through your skin. This includes anything from continuous exposure to environmental pollutants to eating foods that stimulate the inflammatory response in your body like trans fats, excess sugar, excess alcohol, drugs, or foods your body might be sensitive to like gluten or dairy.
- Overuse injuries – Chronic inflammation can occur in muscles, joints, tendons and ligaments in various sports or jobs that require long duration continuous movements. This includes things like tendonitis, carpal tunnel syndrome, osteoarthritis, stress fractures, plantar fasciitis, bursitis, or shin splints.
How can we prevent chronic inflammation?
The only way to get rid of chronic inflammation is to remove the substance(s) that is/are making your immune system over-react. In some case that is easy, don’t eat crap, use proper body positioning and training techniques, let your body recover, and avoid toxins. But if the chronic inflammation is because of hypersensitivity or autoimmune reactions, then obviously it very difficult or not possible to remove the offending substance….but there are ways to calm your immune system down such as natural anti-inflammatories like omega 3 or curcumin.
If we are looking at the chronic inflammation that is involved in the myriad of chronic diseases listed at the beginning of this article, then we actually have a significant amount of control. It always boils down to the same 4 things – diet, sleep, exercise, and stress management.
Hey Wendi, another great article! I would be interested in knowing more about how diet affects chronic inflammation. Rosemary
Cool, I will write one specifically about that 🙂
Hi Wendi NIce article but I have a question for you…
When in Nunavut in late December I turned my right leg and foot so much that I went to the local clinic where they took xrays and found no broken bones. Great – but they said I had soft tissue damage.
I was wrapped with a tensor bandage and given Ibuprofen and tylenol for the pain and inflammation. I used a walking stick for a while till it improved but here in mid January it is still bothering me. I have used ice and raised it when I can. Any suggestions??
Thanks Wilf
Sorry to hear about your injury!! I am glad nothing was broken. Sometimes connective tissue injuries can take a long time to heal. Since it has been a little while now since it happened, you don’t need to use ice unless it looks like it is swelling. Now it would be important to get blood flow and nutrients to the area so it can have the building blocks for making new cells. Warmth and massage, just rubbing it yourself to increase blood flow, and gently moving it around in its range of motion. Also keep taking it easy, you want to move it around but don’t overdo it until it is fully healed. 🙂
THanks Wendi – I will follow your advise
Your explanations of the immune system processes are so helpful. I read this page, though and wanted to comment – as someone who has multiple autommune conditions – genetics is a factor as well. I have exercised daily, ate a consistently health diet, maintained weight etc etc. All the right things. Still got hit with several autoimmune issues. If I ate poorly etc. – sure it would be worse. But certainly the world is filled with people who don’t take care of themselves and do NOT get autoimmune conditions.