Thyroid disease frequently goes undiagnosed (and undertreated). Hypertension often has no symptoms. Diabetes gets a foothold long before your blood sugar levels reveal anything amiss. Narrowing arteries — a process called atherosclerosis — may not announce itself either. But they all have something in common (which itself also lacks “red flag” warning signs, unless you’re paying close attention): inflammation. An immune system reaction that contributes to clotting, an increase in weight, autoimmune diseases, and more, inflammation in your body that’s not related to an injury or infection happens without you knowing it.
“Inflammation has a role in so many diseases through multiple pathways,” says Monica Aggarwal, MD, a cardiologist, adjunct associate professor of medicine at the University of Florida, and co-author of Body on Fire: How Inflammation Triggers Chronic Illness and the Tools We Have to Fight It. “We’re not even fully clear on all the pathways yet. We used to think inflammation was the result of illness. Now we have a better understanding that inflammation is part of the trigger for the illness.”
Why does it matter? Getting a handle on inflammation — via diet and other lifestyle changes — can help you prevent some of these illnesses or more easily treat them, potentially with a reduced need for medication. Let’s take a look at the role inflammation plays in the following common conditions and how you can do some basic testing to reveal what may be going on (your doctor is the best person to decide exactly what to look for, but don’t be afraid to advocate for further testing when warranted).
Type 2 Diabetes
Inflammation has emerged as a major factor in this condition, where cells in the pancreas eventually burn out. One key factor at play in diabetes is insulin resistance. Normally, when you eat something with carbohydrates, a certain amount of glucose (sugar) enters the bloodstream. That triggers an insulin release from the pancreas to help shuttle the sugar into muscles and other cells in the body for storage. Insulin resistance happens when these receiving cells start to ignore insulin’s signaling. The pancreas has to release more and more of the hormone to finally get them to open up. Eventually, the cells in the pancreas that are responsible for sending out insulin wear out.
In addition, eating more calories than you need contributes to weight gain. That added fat tissue is highly inflammatory (new research is looking into how different types of fat cells work to promote insulin resistance). It’s like a systemic inflammation factory.
Check your insulin and blood glucose levels. Blood sugar between 100–125 signals “pre-diabetes” — the beginning of diabetic changes. Anything over 125 is diabetes. But even blood sugar levels above 85 indicate the body is struggling to use insulin the way it should. “Insulin resistance is underdiagnosed,” says Marzena Slater, MD, a practitioner at Root Functional Medicine in Grand Rapids, Michigan. She says blood glucose levels between 70 to 85 are optimal. If the numbers are creeping up, change your diet and exercise habits, STAT!
Daily injuries to the heart — akin to microaggressions — whether from smoking, high blood pressure, or high cholesterol, trigger an inflammatory response in the body, which can lead to narrowing of the arteries. “Blood vessels are lined with endothelial cells that make the vessels soft and smooth and able to dilate,” says Aggarwal. “Cholesterol can trigger the buildup of plaques inside the vessels. Over time, risk factors, such as smoking, high blood pressure, and diabetes, can trigger inflammation and damage the endothelial cell wall, which can cause the plaques to rupture.” That can lead to a heart attack or stroke, depending on where the resulting blockage happens.
Your blood pressure and cholesterol levels will give you an idea of the health of your blood vessels. An hs-CRP (high-sensitivity C-reactive protein) test can tell you if there’s inflammation present, but it won’t tell you where it is. “The most important thing your doctor can do is listen to your story,” says Aggarwal. “From there they can decide which tests you need and what lifestyle changes you’ll need to make.” While your doctor may not readily test inflammatory markers, they are increasingly looking for ways to treat inflammation. The main avenues to do that, says Aggarwal, are by making healthy dietary changes, quitting smoking, exercising more, and managing stress.
Researchers are discovering a link between immune system triggers and depression, which is opening up the development of new treatments for the often disabling condition that affects millions of people. Cytokines, compounds released during an infection, signal the brain that there’s an infection. This can trigger what’s known as “sickness behavior” — loss of appetite, achy joints, fatigue, a desire to be alone, and sleepiness. These effects help conserve energy, thereby bolstering the body’s reserves to fight off the infection. But when chronic inflammation keeps this behavior going, even at a low level, it may trigger depression. Inflammation can also interfere with signals from neurotransmitters, including serotonin, which can also exacerbate depression. One study with 73,000 people, published in JAMA Psychiatry, found that those who had higher levels of C-reactive protein also had a higher risk for depression.
Ask for an hs-CRP test. Again, your CRP levels won’t tell you what’s causing inflammation. From there, start with your diet to see if it makes a difference and work with your doctor and/or therapist on other strategies.
Adipose tissue (aka fat) functions as an inflammation warehouse, storing hormones and churning out compounds that create even more inflammation. In the beginning, increasing inflammation in the body can lead to insulin resistance. Since the cells aren’t using insulin, there’s more hanging around. The problem: Insulin promotes fat storage with excess calories. More fat creates more inflammation and also acts as a storage depot for estrogen, potentially creating a hormonal imbalance that can also promote inflammation. “The balance of estrogen and progesterone can contribute to autoimmune conditions,” says Jenny Bennett, ND, owner of Aria Integrative Medicine in Seattle.
Tracking metabolic changes, including blood sugar, cholesterol, and a simple waist-to-hip measurement, can help you determine how any extra pounds you’re carrying are affecting your body’s metabolism and health.
A complicated yet common condition, asthma can both begin because of inflammation and also create inflammation. A systemic allergic response — with cytokines playing a key role — is at play in up to 70 percent of people with asthma, according to the Allergy & Asthma Network. Some people with this type of asthma have an especially hard time controlling their condition and may require a different type of medication.
Your doctor can look at IgE as well as other markers, in addition to testing air flow.
The term thyroiditis means inflammation in the thyroid. When that inflammation continues, it
can damage the thyroid gland, which secretes hormones used throughout the body. The most common cause of thyroid disorders is Hashimoto’s Thyroiditis, an autoimmune disorder. “When inflammation gets high it speeds up metabolism,” says Bennett. “If it stays high, it can burn out the thyroid gland.” Inflammation from the gut can also trigger changes in the thyroid. An imbalance of bacteria — caused by diet, stress, poor sleep, and even environmental factors — can make it harder to manage your thyroid and also potentially reduce absorption of your medication.
Have your doctor check your TSH as well as levels of T3 and T4, the two main thyroid hormones. If you have a family history of thyroid disorders — whether hyper-or hypothyroid — you may also want to check for antibodies, which can signal the presence of an autoimmune issue.
This condition is characterized by chronic muscle aches in specific areas of the body, fatigue, headaches, anxiety, sleep disturbance, and cognitive shifts. It hasn’t necessarily been seen as an inflammatory condition. However, more research is pointing to inflammation in the central nervous system as contributing to the problem. A 2020 study published in Dermatologic Therapy found that people who had fibromyalgia had an increased number of inflammatory cytokines and mast cells, a type of white blood cell, in the skin, as well as other inflammatory compounds.
Your doctor will test for inflammatory markers, including erythrocyte sedimentation rate (aka “sed rate”), antinuclear antibodies, rheumatoid factor, thyroid function, and more, partially to rule out other disorders.
Neuroinflammation is associated with the buildup of abnormal and damaging proteins that are found in the brains of people with Alzheimer’s as well as other types of dementia, according to a 2020 study from the University of Cambridge that was published in the journal Brain. The study, which looked at people with different types of dementia, found that the more inflammation there was, the more harmful proteins were present in the brain.
Inflammation can also make the blood-brain barrier more porous, allowing an influx of inflammatory compounds that kill normal, healthy cells. According to a paper published in Science Translational Medicine, almost 60 percent of adults over age 70 have a leaky blood-brain barrier. Even people without dementia who have higher levels of brain inflammation can experience changes in cognition.
There are various brain scans and other tests that can help your doctor diagnose dementia, based on your signs and symptoms.
Poor dental health can not only trigger inflammation and infection in the gums. It also links to conditions like heart disease and diabetes. Once your immune system gets wind of an infection occurring in the mouth, it triggers action throughout the body. This leads to systemic inflammation. Infection in the mouth also provides a highway for bacteria and other pathogens to enter the blood stream.
Besides brushing and flossing, see your dentist for regular checkups. He or she can spot the early stages of gum disease and give you tips for treating it.
Inflammatory Bowel Disease (IBD)
Chronic inflammation in the gastrointestinal tract, increased gut permeability, and an imbalance of gut bacteria are the hallmarks of this disease, which includes Crohn’s and ulcerative colitis (UC). Patients may not have all these elements, which makes treating the condition very individualized. What works for one person may not work for another. The inflammation that occurs in the small and large intestine can inhibit the absorption of key nutrients and “fire”-fighting compounds, contributing to further inflammation, anemia, and malnutrition. Crohn’s and UC differ in how they affect the system. Crohn’s can infiltrate many layers of the GI tract and the lesions it causes can appear sporadically, mainly in the small intestine. UC mainly affects the inner lining of the large intestine. It’s often associated with blood in the stool.
Besides a sed rate, hs-CRP and complete blood count, your doc will order specific blood and stool tests and imaging to come to a diagnosis.
Affecting up to 10 percent of women of reproductive age, this condition is marked by endometrial tissue (the kind normally found inside the uterus) migrating outside the uterus to other structures, such as the bladder, colon, and even the diaphragm and brain (it can cause seizures and headaches). These lesions create a chronic inflammatory environment —
often in the area surrounding the reproductive organs — and release estrogen and fluid which communicates with the immune system, ramping it up like a bellows on a fire. The condition is a common cause of infertility.
Your doctor will do a pelvic exam and an ultrasound and possibly an MRI. A laparoscopy, where your doctor inserts a tiny tube into your lower belly to see what’s happening, is the best way to diagnose it. There are no specific blood tests for endometriosis. A CA-125 test may be able to tell you if there’s a protein linked with endometriosis, but it’s not specific to that condition. Researchers are exploring other blood markers to help identify the condition as well. “Inflammation is a binding factor in all illnesses,” says Aggarwal. “The future of medicine will be figuring out the targets and triggers for this inflammation to better treat it.”
Why COVID-19 Is Such a Threat
You’re probably over reading about this condition, but it’s so dangerous to so many because of inflammation. In some people it can cause an outsize inflammatory response in the body. And if there’s already inflammation present — heart disease, an autoimmune condition, diabetes, or advanced age — it’s even worse, which is why these people are at higher risk.
When the virus infects the body, it reacts with both “barrels” of the immune response — innate and adaptive. Sometimes, a person’s innate reaction can be delayed, which can bring on a more pronounced inflammatory response, according to a recent review published in the International Journal of Clinical & Experimental Pathology. The immune system unloads on the virus even more, resulting in what’s called a cytokine storm, which can be more damaging than the virus itself. The bottom line: Reduce inflammation to lower your risk of chronic disease, which in turn decreases your chances of getting sicker from the coronavirus (and other infectious conditions, like the flu and pneumonia).
A version of this article appeared in our partner magazine, The Complete Guide to Anti-Inflammation.