What Causes Inflammation?

Inflammation is associated with many chronic diseases, conditions, and risk factors. Learn what causes inflammation and how to reduce it.

What causes inflammation?

It’s hard to imagine anyone who hasn’t had first-hand experience with inflammation. It occurs in everything from a pimple to the swelling from an injury or accident. Inflammation is also associated with arthritis and other conditions.

Inflammation can cause pain, but it can also be beneficial. In fact, inflammation prompts your immune system to respond to an infection. For example, inflammation helps if you suffer a cut or abrasion. Your immune system sends white blood cells (leukocytes) to the area to help fight any infection and promote healing. Especially if you develop an infection, your immune system can cause some swelling, as the leukocytes fight disease-causing pathogens.

The same response occurs when you encounter a virus.

Sometimes this immune response causes inflammation for other reasons. Exposure to toxins, for example, can trigger inflammation, as can chronic stress, obesity. and autoimmune disorders. In such cases, instead of inflammation occurring to help heal a problem and then going away when the injury or illness is much better or gone, the inflammation persists over time.

Whatever the cause, a chronic state of inflammation is now linked to numerous health problems — either as a direct cause or a contributing factor — including heart disease, arthritis, depression, Alzheimer's disease, and even cancer. 

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What is inflammation?

Advanced technology has uncovered how inflammation starts at the cellular level.

Scientists have found that inflammation, no matter where it occurs, isn’t automatic. Instead, tiny molecular structures called inflammasomes work as immune system sensors and receptors to regulate inflammation-related molecules in the aftermath of an injury. One type of signaling molecule (a cytokine) is secreted from immune cells to cause inflammation. That inflammation may be needed and appropriate in many illnesses and injuries.

But sometimes, these inflammatory cytokines are produced in excess, contributing to diseases that involve chronic inflammation, studies show.

That type of inflammation, known as metainflammation, differs from classic inflammation in important ways. A review of the research about metainflammation, published in the journal Preventing Chronic Disease, explains it is “low-grade, causing only a small rise in immune system markers, but is persistent and results in chronic, rather than acute loss of bodily equilibrium.”

It also produces homegrown antigens or substances that cause your immune system to produce antibodies against them. This response in turn prompts inflammation.

“In essence, although classical inflammation has a healing role in acute disease, metainflammation, because of its persistence, may have a mediating role, helping to aggravate and perpetuate chronic disease,” the review concludes.

“In recent years, we've come to accept that inflammation plays a role in many chronic diseases, but it's about an imbalance — too many pro-inflammatory chemicals and not enough anti-inflammatory ones," Moise Desvarieux, MD, PhD, an inflammation researcher at Columbia University's Mailman School of Public Health, said.

Cancer, which globally results in more than 8 million deaths a year, has become a particular focus of research on the connection between inflammation and disease, according to Robert A. Weinberg, PhD, of the Massachusetts Institute of Technology’s Whitehead Institute for Biomedical Research. He discussed this change in research direction in his influential textbook, “The Biology of Cancer.”

How to reduce inflammation

It’s probably not surprising that too much stress in your life can cause health problems. That connection has emerged in many studies. You may not know, however, that chronic stress may be causing chronic inflammation in your body in ways that are not obvious. So, it makes sense to talk to your doctor and lower your stress levels with exercise, meditation, and other relaxation techniques.

Although there are many different theories about how to prevent or reduce chronic inflammation, most agree on one thing: A healthy diet rich in vegetables, fruit, fiber, phytochemicals, and other nutrients can play a key role in reducing your body’s chronic inflammatory response. Research suggests losing weight and exercise can help lower chronic inflammation, as well.

Some medications may help reduce chronic inflammation, too. For example, the effectiveness of statins in reducing heart disease may lie, in part, not only in the drugs’ ability to reduce cholesterol levels but also because they reduce inflammation. Ask your doctor about any drugs that have been approved for use against chronic inflammation.

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