CRP Blood Test Results Explained


The CRP blood test measures the C-reactive protein. This is a blood test marker that indicates there is inflammation occurring somewhere in the body. This protein is produced by the liver and its levels will rise in response to increased levels of inflammation. As an acute phase reactant, CRP is present in all types of inflammation, so the blood test cannot distinguish between acute or chronic health concerns.

CRP will be released into the blood within a few hours of an injury or the beginning of an infection. It may not be a diagnostic blood test, but it can be used with other tests to help determine the presence and cause of an inflammatory condition.

When Is the CRP Blood Test Ordered?

The CRP blood test is commonly ordered when someone is suspected of suffering from a bacterial infection. It is a common blood test for newborns and infants when they begin to show the signs of an infection. This may include chills, a fever, rapid breathing, and an increased heart rate.

This blood test is also frequently ordered as a way to monitor the effectiveness of a treatment plan. It can determine if a condition like lupus or rheumatoid arthritis may be increasing in severity. The CRP blood test has also been found to be useful in monitoring conditions like inflammatory bowel disease, vasculitis, and pelvic inflammatory disease because it can detect flare-ups in addition to monitoring the treatments being implemented.

What Do My CRP Blood Test Results Mean?

In basic terms, a CRP blood test will be either positive or negative. The levels of CRP that are in the blood are generally low because it is only produced by the liver when there is an inflammatory condition present.

Current testing practices offer a range of CRP that is from 10 to 1000 mg/L. What your specific test results mean will need to be interpreted by your doctor to determine what your test results mean. In general terms, the closer you get to 10 mg/L, then the lower the level of inflammation there will be in the body.

When CRP levels are high, then this indicates that inflammation is present somewhere in the body. This blood test cannot indicate where that inflammation may be occurring. If several blood tests are ordered over a period of time and they indicate a rising level of CRP, then those results would also fit into this category. High CRP levels that are persistent can also be an indication that there is a higher risk of cancer development in the future.

If CRP levels are low, then this generally indicates a “normal” test result.

Sometimes testing will show that CRP levels will initially rise, but then drop over time. This is an indication that the inflammation is resolving or that the body is healing. It is also an indication that a treatment plan is working as intended.

Some medical providers may offer what is known as a “high specificity” CRP blood test. This test has a range of 0.5 to 10 mg/L and is usually ordered alongside a lipid profile to determine the potential future risk for heart problems. Anything below 1 mg/L is considered to be a good result, while readings greater than 3 mg/L indicate a risk for cardiovascular disease.

Here’s What You Need to Know

Some people have levels of CRP that are naturally higher. This is usually seen in individuals who are overweight or obese according to BMI measurements. Women who are in the later stages of a pregnancy will also have naturally higher CRP levels.

Certain medications or treatment programs have also been known to raise CRP levels. This includes hormone replacement therapies, estrogen, and oral contraceptives.

Individuals who are suffering from a chronic inflammatory condition will usually have a raised CRP level compared to those who do not have any inflammation. This can be caused by any number of conditions, so a diagnosis cannot occur from this one test alone. If arthritis, IBD, lupus, or a different pathological condition is suspected, then further testing to determine a specific diagnosis will likely be required.

The CRP blood test can be a useful tool to help determine certain risk factors while also providing evidence of acute or chronic inflammation. If you suspect that you may have a condition that is causing ongoing inflammation, then speak with your doctor about this blood test. It, along with other tests and evaluations, can help to create a treatment plan, if needed, to restore your health.