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What is inflammation?

What is inflammation?

Dubbed the ‘scourge of modern life’, inflammation has become a hot topic of discussion in the health and wellness zeitgeist (1). The truth is we have a love-hate relationship with inflammation. It’s not explicitly good or bad.
Inflammation is a natural biological response to injury or sickness. It’s a critical part of the body’s defence system. Sometimes, however, this intrinsic ‘alarm’ can spiral out of control, leading to chronic, low-grade inflammation that harms rather than heals.
It’s becoming increasingly clear that 21st-century living fosters levels of sustained, unresolved inflammation that didn’t exist decades ago. Our immune systems are constantly activated in this new environment of ultra-processed foods, air pollution, and stress, increasing inflammatory markers and worsening health outcomes (2).

Types of inflammation

Most of us recognise inflammation on the surface: it causes local heat, swelling and pain in an area that’s injured or under attack. Though uncomfortable, inflammation is the cornerstone of the body’s healing process. However, this mechanism is so powerful – and potentially so destructive – that it can become a problem if it persists (3).

Acute inflammation

Acute inflammation is the immune system’s natural response to any injury or traumatic event – from a scraped elbow to a virus. The body releases white blood cells to support and rehabilitate the affected area. Acute inflammation usually dissipates within a few hours or days (4).

 What are the symptoms of acute inflammation?

In the case of acute inflammation, you may notice warmth, redness, or swelling around an injured spot – if you cut your finger, for instance. The same goes for when you have a virus. You may experience pain and swelling, as well as muscle and joint aches. These symptoms mean acute inflammation is speeding up the healing process.

Chronic inflammation

Chronic inflammation, on the other hand, is a longer-lasting immune response that lingers over months or years. It occurs when the body continues to send white blood cells on the rampage when there’s no outside threat. Low-grade, inappropriate inflammation can disrupt normal bodily functions and attack otherwise healthy organs and tissues (5).

What are the symptoms of chronic inflammation?

Although chronic inflammation is often ‘invisible’, you may experience physical discomfort, fatigue and insomnia, weight gain, changes in mood, gastrointestinal issues, and frequent infections. Sustained, unresolved inflammation may also increase the risk of autoimmune disorders and allergies. But perhaps most concerning, chronic inflammation is a common thread that runs through nearly all modern diseases and even ageing itself.

What causes inflammation?

As hunter-gatherers, our immune systems evolved to be overly protective to survive infections, pathogens, and other dangers of ancestral times. In this historical setting, such a robust inflammatory response was appropriate. But our modern environment has transformed since then. Now, the processed food we eat, the polluted air we breathe, and the unrelenting stress we experience continually trigger our hypersensitive immune systems, which pave the way for inappropriate inflammation (6).  


Thanks to widespread pollution and mass global production of plastics, microplastics – found in single-use water bottles, storage wraps, and plastic containers – are ubiquitous in our modern world. These man-made materials can leech into the food supply, which may contribute to low-grade inflammation in the body (7).


Pesticides are used in much of the produce we eat. However, these substances are toxic by design and intend to harm living organisms. Like microplastics, pesticides can migrate onto food. And their inherent toxicity may play a role in sustained, unresolved inflammation (8).

Air pollution

Air pollution is another by-product of mass industrialisation and development. Increasing scientific evidence suggests long-term exposure to pollution particulates can produce systemic inflammation in the body (9).

Lack of quality sleep

Sleep is the cornerstone of good health. But many things rob us of our precious shuteye in the modern world: Netflix, work emails, anxiety, the 24-7 news cycle, social media – the list could go on. Sleep loss and the disruption of circadian rhythms (the body’s internal clock) increase inflammatory molecules (10). And that’s why shift workers, who have irregular sleep cycles, often have higher inflammatory markers (11).

Smoking and alcohol

Cigarette smoking, nicotine, and excessive alcohol consumption are known to increase systemic inflammation in the body (12).

Gut issues and poor diet

Most inflammatory issues start in the gut, where the gut microbiome – the collective name for the trillions of bacteria, fungi, and viruses – resides. A typical Western diet, which is high in ultra-processed foods – often loaded with saturated fats and refined sugar – and low in fibre-rich foods (fruits, veggies and plants) can cause ‘dysbiosis’, an imbalance of good to bad gut bacteria (13). Such disharmony and dysregulation can make the gut a more inflammatory environment.

Elevated blood sugar

Eating too much sugar can elevate blood glucose levels. In most healthy people, the body responds to sugar by secreting the hormone insulin, which helps restore blood glucose levels to normal. However, if you consistently have excessive glucose in your bloodstream – often down to overconsuming refined carbohydrates, sugary drinks, and other foods that spike glucose – your cells may become resistant to insulin, causing your overall blood sugar to rise. This state is known as insulin resistance – and it can trigger an inflammatory response in the body (14).

Weight gain

Weight gain and inflammation have a bidirectional relationship: weight gain can lead to inflammation, and inflammation can lead to weight gain. One study reported the inflammatory marker, C-reactive protein (CRP), increased as weight increased (15).


Never before have we been more virtually connected and less physically connected. But this isn’t how we evolved as a species. Humans are social beings. Therefore, isolation can become a source of stress, with research suggesting loneliness increases systemic inflammation (16).

What diseases are caused by inflammation?

Across the globe, research suggests three out of five people die from diseases related to inflammation (17). This, they say, makes chronic inflammatory diseases the most significant cause of death worldwide. Chronic inflammation is thought to be linked to the development of several conditions, including the following:

Meanwhile, medical disorders that cause chronic inflammation include autoimmune conditions, which result from the immune system attacking healthy tissue instead of pathogens. Rheumatoid arthritislupustype 1 diabetespsoriasismultiple sclerosis and Crohn’s disease are some examples of autoimmune conditions.
You can read our guide to autoimmune conditions here.

Find more information

When it comes to inflammation, you can have too much of a good thing. Thankfully, focusing on the four pillars of health – diet, movement, sleep, and relaxation – can help keep low-grade, inappropriate inflammation under control.
If you found this article on inflammation helpful, you can find further content in our pharmacy health library. Alternatively, please get in touch with our team of expert Nutrition Advisors, who will be happy to help with any enquiries.


  1. Snyder, W. (2021) The good, the bad and the ugly of inflammation, Vanderbilt Medicine. Available at:

  2. McDade, TW. (2012) Early environments and the ecology of inflammation. Proc. Natl Acad. Sci. USA 109, 17281–17288; Carrera-Bastos P, Fontes-Villalba M, O’Keefe JH, Lindeberg S & Cordain, L. (2011) The western diet and lifestyle and diseases of civilization. Res. Rep. Clin. Cardiol 2, 15–35.

  3. Furman, D., Campisi, J., Verdin, E. et al. (2019) Chronic inflammation in the etiology of disease across the life span. Nat Med 25, 1822–1832.

  4. (2022) Acute inflammatory response - statpearls - NCBI bookshelf. Available at:

  5. Bennett JM, Reeves G, Billman GE & Sturmberg JP. (2018) Inflammation–nature’s way to efficiently respond to all types of challenges: implications for understanding and managing “the epidemic” of chronic diseases. Front. Med 5, 316.

  6. Furman, D., Campisi, J., Verdin, E. et al. (2019) Chronic inflammation in the etiology of disease across the life span. Nat Med 25, 1822–1832.

  7. Kwon JH, Kim JW, Pham TD, Tarafdar A, Hong S, Chun SH, Lee SH, Kang DY, Kim JY, Kim SB, Jung J. (2020) Microplastics in Food: A Review on Analytical Methods and Challenges. Int J Environ Res Public Health 17(18):6710.

  8. Ruíz-Arias, M.A., Medina-Díaz, I.M., Bernal-Hernández, Y.Y. et al. (2023) Hematological indices as indicators of inflammation induced by exposure to pesticides. Environ Sci Pollut Res 30, 19466–19476.

  9. Pope, C.A. et al. (2016) Exposure to fine particulate air pollution is associated with endothelial injury and systemic inflammation. Circulation Research 119(11), 1204–1214.

  10. Comas, M., Gordon, C.J., Oliver, B.G. et al. (2017) A circadian based inflammatory response – implications for respiratory disease and treatment. Sleep Science Practice 1, 18.

  11. Bjorvatn B, Axelsson J, Pallesen S, Waage S, Vedaa Ø, Blytt KM, Buchvold HV, Moen BE, Thun E. (2020) The Association Between Shift Work and Immunological Biomarkers in Nurses. Front Public Health 8:415.

  12. Federation of American Societies for Experimental Biology. (2016) "Missing link between smoking and inflammation identified." ScienceDaily. ScienceDaily.

  13. Shi Z. (2019) Gut Microbiota: An Important Link between Western Diet and Chronic Diseases. Nutrients 11(10):2287.

  14. Collier B, Dossett L, May A, Diaz J. (2008) Glucose control and the inflammatory response. Nutrition in Clinical Practice 23(1):3-15.

  15. Tuomisto, K. et al. (2019) Role of inflammation markers in the prediction of weight gain and development of obesity in adults – a prospective study, Metabolism Open, 3, 100016.

  16. Liu YZ, Wang YX, Jiang CL. (2017) Inflammation: The Common Pathway of Stress-Related Diseases. Front Hum Neurosci 11:316.


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Disclaimer: The information presented by Nature's Best is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.

Our Author - Olivia Salter


Olivia Salter has always been an avid health nut. After graduating from the University of Bristol, she began working for a nutritional consultancy where she discovered her passion for all things wellness-related. There, she executed much of the company’s content marketing strategy and found her niche in health writing, publishing articles in Women’s Health, Mind Body Green, Thrive and Psychologies.

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