Inflammation has been connected to heart disease, stroke and cancer. But what is inflammation? How do you know if you have it? How is it measured or tested? And what should you do about it? A family doctor answers.

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inflammation-burnby Eric McLaughlin, M.D., M.P.H.

Doctors and health-care providers like to use big words. We go to school for many years just to learn these big words and, like children, we enjoy showing off.

Take “inflammation.” Not too long ago, when we said “inflammation,” we usually meant what happens when you get a cut or scrape. Swollen, red skin was “inflamed.” Your joints could be inflamed, too, if you had arthritis.

But now, we’re using “inflammation” all over the place. Studies in the news keep connecting it to about every common disease in the book—including heart disease, stroke and cancer.

Inflammation is both simple and complex—both good and bad. But there is something you can do about it. In fact, the solution is pretty simple. After learning what inflammation actually is, you’ll see why.

What Is Inflammation?

Think of a skinned knee and the redness, swelling, pain and warmth that surround the scrape almost immediately. That’s inflammation—tissue’s reaction to injury. In this case, it’s good. Swelling creates a tight barrier, keeping bacteria out. The redness and warmth are from an increased blood supply, providing defense mechanisms like white blood cells. A basic role of isolating injury, destroying invaders and healing damaged tissue, inflammation is vital.

When you get inflammation inside your body, though, you can have issues. The problems start when it happens in a dangerous spot, such as the coronary arteries.

inflammation-detectiveHow Inflammation Is Measured

We can’t dissect your body to see if your arteries are swollen. But we can measure signs of inflammation. Most commonly, we use one of two tests: erythrocyte sedimentation rate or C-reactive protein.

ESR Test

Invented in 1897, the ESR, or sed rate, started to get used widely around the 1920s. In recent memory, doctors have mainly employed it to look for arthritis or infection. But it indicates any kind of inflammation.

To conduct the test, we just put some blood in a skinny tube and let it sit for an hour to see how quickly it settles. If you have inflammation, certain proteins that collect on red blood cells’ surfaces make them stick together in columns. These settle faster.

CRP Test

The CRP has been around since the 1930s, but recent years have seen its publicity skyrocket.

It all started in the ‘90s, when Paul Ridker, M.D., and Brigham and Women’s Hospital discovered that measuring the inflammation-related C-reactive protein may “predict high risk of cardiovascular disease even when cholesterol is low,” explains Brigham and Women’s spokesman Kevin C. Myron. Their invention, the hs-CRP—a “higher specific” test—is the one getting the most attention because it’s more accurate and, well, specific. Then again, it’s more expensive and takes longer to get results.

Another bit of CRP controversy: Dr. Ridker and Brigham and Women’s Hospital have been involved in inflammation studies that have helped publicize the hs-CRP test. They earn royalties from that test.

When Is Inflammation Dangerous?

inflammation-1Just as inflammation on your skin results from injury, inflammation inside your body comes from cell damage. This can be from physical trauma or any other insult. High blood pressure, poor glucose control in diabetes, cigarette smoke and increased cholesterol cause inflammation in arteries.

Researchers are looking at harmful ways inflammation affects your body. One main issue they’re examining is heart disease.

The Survival Doctor's Guides to Wounds and BurnsSome research has shown a relationship between inflammation and heart attack. The double whammy: People with inflammation may be less likely to survive a heart attack and more likely to have arteries close up again that were opened with stents or balloons. Perhaps, scientists say, inflamed arteries are more likely to build up plaques and have these plaques break off and travel to the heart. Inflammation’s ties to stroke probably work the same way.

Cancer is another matter. We still understand some types of cancer poorly, but, for example, smoking causes long-term cellular irritation. We’re not yet sure of the role inflammation plays.

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How to Treat Inflammation

inflammation-2In the classic The Art of War, Chinese philosopher Sun Tzu wrote, “If you know the enemy and know yourself, you need not fear the result of a hundred battles.” He would have made a good doctor.

If we want to stop inflammation, we can prevent what causes it—attacking the problem at its source.

Maintaining a healthy blood pressure; watching your cholesterol; stopping tobacco; and, for diabetics, controlling your glucose, are important steps. Researchers are even looking into infections that cause chronic inflammation that affects the heart, with the herpes virus and the Chlamydia pneumoniae bacteria (not the same as the STD chlamydia) getting a lot of attention.

One of the most important weapons in the battle against inflammation and heart disease may be aspirin. Aspirin is a wonder drug, capable of doing many things. While we don’t know the exact way it works, it does decrease fevers, inflammation, pain and blood clots. These are some of the basic causes and results of the inflammatory process. Clearly, aspirin plays a role, but at what level remains to be seen.

Can You Feel Inflammation?

You can tell when your skin is inflamed. It hurts, for one thing. Inflammation inside the body is more difficult to detect. The arteries and many internal organs don’t have the pain sensors the skin has. Particularly if you have inflamed arteries, you won’t feel a thing.

Who Should Be Tested for Inflammation?

One test for inflammation is the C-reactive protein measurement. Some clinicians are advocating including it routinely, as another part of the cholesterol screening. One crimp in such a plan: The CRP test detects any inflammation, no matter where it is. A skinned knee, flu, arthritis and infections are common causes of elevated CRP. Getting to the root can take some time and require multiple tests.

People with a normal or slightly elevated cholesterol profile might benefit from having a CRP test done since it may suggest another risk factor for heart disease. But overall, experts suggest most people shouldn’t ask for or expect a CRP. This may change, but for now the data is unclear.

How to Prevent Inflammation

You can help prevent inflammation by doing the same things you already know are good for you. Controlling blood pressure and diabetes, getting regular exercise, eating a low-fat diet with fruits and veggies, and cutting out tobacco are ways to decrease the root causes of inflammation and heart disease. That way, you won’t have to worry about that CRP test anyway.


ERIK MCLAUGHLIN, M.D., M.P.H., is a family doctor resident in Chicago. He runs the travel health website

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Original article appeared in March/April 2009 issue of My Family Doctor magazine.

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