What Is Inflammation?

The human immune system is fantastic at protecting against intruders like viruses and bacteria. One of the tools it uses to keep us safe is inflammation. Ultimately, the inflammatory response is a process that’s meant to protect you, but it can cause problems if it gets out of control.

What is inflammation?

Inflammation is your immune system’s response to infection or injury. When you cut your foot or develop a cold, your body is ready, sending defenders such as white blood cells to fight off bacteria, viruses and other pathogens.

There are two main types of inflammation: acute and chronic.

What is acute inflammation?

“The main causes of acute inflammation are viruses, bacteria and protozoa, or single-celled parasites,” explains Dr. Stefano Guandalini, MD, professor emeritus at the University of Chicago, and one of the world’s leading experts on celiac disease, an autoimmune condition that causes inflammation.

“In all of these cases, inflammation is a normal response by the damaged tissue that releases chemical substances to activate white blood cells so they can try and kill the intruder.”

When your body encounters a virus like COVID-19 or the common cold, or a bacterial infection like strep throat, acute or temporary inflammation is its first defense.

Signs of acute inflammation

There are five classic or cardinal signs of acute inflammation:¹ ²

• Visible redness
• Swelling 
• Pain
• Heat at injury site
• Loss of function
  

What is chronic inflammation?

While acute inflammation is common and often doesn’t require much, if any, treatment, chronic inflammation, or long-term inflammation, is a different story. With this immune response, your immune system continues releasing chemicals, white blood cells or both to fight a perceived threat — even if you aren’t necessarily sick or injured. Sometimes your immune system may even mistake its own cells or tissues as harmful invaders.

Sometimes chronic inflammation occurs as a response to ongoing foreign substances, like toxins from cigarette smoke, excessive fat cells (especially in the belly), or a build-up of cholesterol in the arteries.³

“Chronic inflammation is a low-grade inflammatory process that accompanies a variety of conditions,” says Dr. Guandalini. “Instead of it being a beneficial healing process, it can be very detrimental.”

Signs of chronic inflammation

According to Dr. Guandalini, medical professionals can’t specifically diagnose chronic inflammation because it’s a feature of many diseases and conditions, each with their own set of diagnostics and treatment plans. 

However, common signs of chronic inflammation can include:⁴ ⁵

• Gastrointestinal pain
• Joint or muscle pain
• Fatigue
• Insomnia
• Depression
• Anxiety
• Fever
• Weight loss or gain
• Rashes

How do you know if you have chronic inflammation?

Chronic inflammation isn’t a diagnosis so much as a clue that something’s wrong.

For decades, labs have used C-reactive protein (CRP) tests to measure inflammation levels in the body.

Dr. Guandalini notes that while high CRP results can indicate the presence of an inflammatory disorder such as inflammatory bowel disease, Crohn’s or ulcerative colitis, they don’t show where inflammation is located or what is causing it. 

Furthermore, even low levels of C-reactive protein can be a clue that something’s wrong, which is why healthcare professionals now turn to something called a high-sensitivity C-reactive protein (hs-CRP) test, which is — you guessed it — more sensitive.

Inflammation levels too high? Here’s what to do

CRP and hs-CRP tests provide important information, but they don’t paint a complete picture. If your inflammation levels are high, your doctor may order other tests to better understand why.

“The hs-CRP test needs to be viewed as part of a comprehensive diagnostic and therapeutic plan that must be discussed with your doctor and tailored for each individual’s needs, including family history and other risk factors,” says Dr. Guandalini. “Never initiate self-treatment with drugs or other alternative forms of therapy like a gluten-free diet or natural medicines before having been fully assessed by a doctor.”

If you suspect chronic inflammation or have been diagnosed with an inflammatory condition, Dr. Guandalini recommends periodically checking your hs-CRP levels and discussing them with your healthcare provider.

What are some common inflammatory diseases?

There are many inflammatory diseases and conditions. Here are some common ones:⁵ ⁶ ⁷

• Alzheimer’s disease
• Asthma
• Autoimmune diseases
• Cancer
• Diabetes
• Endometriosis
• Fatty liver disease
• Inflammatory bowel diseases
• Rheumatoid arthritis
  

According to the American Heart Association, inflammation is also associated with heart diseases such as heart attack and stroke. “Although it is not proven that inflammation causes cardiovascular disease, inflammation is common for heart disease and stroke patients.”⁸ Myocarditis and pericarditis are also types of heart inflammation that are chronic.⁹

Unpreventable inflammatory diseases 

Some people are genetically predisposed to certain chronic diseases, conditions and autoimmune disorders, and there’s not a lot they can do to stop them from developing. Degenerative arthritis, lupus, type 1 diabetes, Crohn’s disease, celiac disease and multiple sclerosis all fall under that category.

Preventable inflammatory diseases 

Then again, there are inflammatory conditions — including heart disease and some cancers — that are linked to lifestyle factors like smoking, obesity, stress and diet, says Dr. Guandalini. These diseases can potentially be avoided through positive lifestyle habits, like eating a healthy diet, exercising and avoiding or quitting smoking.

At-home treatments for inflammation

Each inflammatory disease comes with its own specific treatment. If you have celiac disease then you’ll need to stop eating gluten, says Dr. Guandalini, while if you have an inflammatory bowel disease, you may be prescribed steroids or biologics. 

That said, there are some things you can do to reduce overall inflammation, especially: 

• Getting regular exercise
• Adopting an anti-inflammatory diet
  

“King among these ‘home remedies’ for inflammation is physical exercise,” says Dr. Guandalini, noting that as long as your physician agrees, a daily 30-minute walk can be super-beneficial. 

“Diet is important too,” says Dr. Guandalini. He suggests trying an anti-inflammatory diet such as the Mediterranean diet, or simply reducing inflammatory items such as meat, sugar, alcohol and processed foods while increasing anti-inflammatory foods like fatty fishes, fruits, veggies, nuts and whole grains. He also says taking a probiotic may help, noting that research in this area is evolving, but promising.

Summary

Acute inflammation is a normal and temporary response to injury or illness, while chronic inflammation can indicate a range of conditions. Speak to your doctor if you suspect you may have an inflammatory disease or condition, and consider periodic hs-CRP testing. Some chronic inflammatory diseases are genetic and some are preventable. Either way, regular exercise and a healthy diet can help reduce inflammation.