While testing can be beneficial in specific cases, it’s not essential for everyone.

Let’s be honest: inflammation doesn’t have the best reputation. And there’s good reason for that. Chronic inflammation is linked to various long-term health conditions and mortality rates. Suppose you were to base your health knowledge solely on media headlines. In that case, you might believe that eliminating inflammation would be the cure-all for everything from heart disease to cancer, cognitive decline, and even the aging process itself.

However, this isn’t accurate.

Nevertheless, recent years have seen significant advances in our knowledge of how ongoing inflammation affects our health. This growing understanding leads to three key questions that many people ask: Is it possible to have inflammation without being aware of it? How can I determine if I have inflammation? And what tests are available to detect it? The answer to the last question is yes, several blood tests exist to measure inflammatory markers.

Inflammation testing methods

Medical practitioners regularly use several well-established tests to detect inflammation. These tests measure biomarkers that indicate an acute phase reaction in the body. However, it’s crucial to understand that these tests cannot differentiate between short-term inflammation, which might occur with an infection, lung inflammation, or physical trauma (tissue injury), and the more concerning chronic inflammation often associated with conditions like diabetes, excess weight, or autoimmune diseases. Recognizing this distinction is crucial.

Here are four widely used inflammation tests:

Erythrocyte sedimentation rate (sed rate or ESR).

This examination measures the speed at which red blood cells descend in a vertical blood tube. Inflammation causes these cells to fall more rapidly, as increased blood proteins cause cell clustering. While normal ranges vary between laboratories, readings of 20 mm/hr or below are typically considered normal, while readings exceeding 100 mm/hr indicate significant inflammation. A high sed rate or high sedimentation rate can be indicative of various inflammatory conditions.

C-reactive protein (CRP).

This liver-produced protein typically increases during inflammation. Normal readings fall below 3 mg/L. Values above 3 mg/L often indicate elevated cardiovascular risk, while systemic inflammation can push CRP levels to 100 mg/L or higher. High C-reactive protein and sed rate together can strongly suggest the presence of inflammation.

Ferritin.

This blood protein indicates the body’s iron storage levels. It’s commonly checked when evaluating iron-deficiency anemia (where levels are low) or iron overload (where levels are high). However, inflammation also causes ferritin levels to rise. Normal ranges vary by laboratory and gender, with men typically having higher levels, but 20 to 200 mcg/L is generally considered normal.

Fibrinogen.

While primarily used to assess blood clotting function, this protein’s levels typically increase during inflammation. Normal fibrinogen readings range from 200 to 400 mg/dL.
When comparing ESR vs CRP, it’s important to note that CRP levels tend to rise and fall more quickly in response to inflammation, while ESR changes more slowly.

The value of inflammation testing

In specific circumstances, inflammation testing can provide valuable insights.

Diagnosing an inflammatory condition.

A prime illustration of this is giant cell arteritis, an uncommon disorder where ESR levels are consistently elevated. When patients present with characteristic symptoms like sudden severe headaches and jaw pain, an elevated ESR can strengthen the likelihood of this diagnosis, while normal ESR readings typically indicate otherwise. Other conditions that may cause elevated CRP and ESR levels include polymyalgia rheumatica and inflammatory bowel disease.

Monitoring an inflammatory condition.

In cases of rheumatoid arthritis or systemic lupus erythematosus, healthcare providers utilize ESR, CRP, or both markers to evaluate disease activity and treatment effectiveness. Elevated ESR and CRP with joint pain can be indicative of active inflammation in these conditions.

It’s important to note that these diagnostic tools aren’t infallible. There are instances where inflammation exists but tests fail to detect it (false negatives). Conversely, test results might suggest inflammation when none is present (false positives). In some cases, you might see a high sed rate with normal CRP, or high CRP with normal sed rate, which can complicate interpretation.

Should you be routinely tested for inflammation?

Current medical practice and expert guidelines don’t recommend inflammation testing as part of standard preventive care for the general adult population.
For cardiac risk assessment, CRP testing is recommended for specific individuals, particularly those with intermediate heart attack risk (neither high nor low), to help determine appropriate preventive measures. However, research indicates that for most individuals, routine CRP testing adds minimal value beyond evaluating traditional risk factors, including hypertension history, diabetes, smoking habits, elevated cholesterol, and family cardiac history.
Interestingly, the only entities consistently advocating universal inflammation testing without specific medical indication are companies marketing these tests directly to consumers.

Inflammation may be silent — so why not test?

While it’s accurate that chronic inflammation can be asymptomatic, conducting blood tests for inflammation without clear medical reasoning is less beneficial than receiving comprehensive healthcare that screens for common inflammation triggers, including:

• obesity
• diabetes
• cardiovascular conditions (encompassing heart attacks and strokes)
• hepatitis C and similar chronic infections
• autoimmune disorders.

Traditional medical evaluations for most of these conditions typically don’t require specific inflammation testing. Your healthcare providers can recommend appropriate treatments if any of these conditions are diagnosed.

The bottom line

While inflammation testing serves an important purpose in medical evaluation and monitoring certain conditions like rheumatoid arthritis, its value as a routine screening tool for the general population remains unproven. The ESR/CRP blood test combination can be useful in specific clinical scenarios, but it’s not necessary for everyone. What causes high CRP and ESR levels can vary widely, from infections to autoimmune diseases, and interpretation should always be done in the context of a patient’s overall clinical picture.

A more effective approach involves maintaining healthy lifestyle practices and receiving regular medical care to identify and manage conditions that contribute to harmful inflammation. If you’re concerned about inflammation, discuss with your healthcare provider whether tests like CRP and sed rate would be appropriate for your specific situation.

Source:
Robert H. Shmerling (December 18, 2024). Should you be tested for inflammation? https://www.health.harvard.edu/blog/should-you-be-tested-for-inflammation-202203292715. Accessed May 5, 2025

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