Primus Pathology Laboratory

C-Reactive Protein (CRP) Test

Last Updated on July 28, 2022 by Dr. Neeraj Gujar


C-reactive protein is a substance that the liver produces in the body in response to inflammation. The CRP test measures the level of this protein in the blood. In short, the CRP test means a test done to diagnose any acute or chronic health conditions that can cause inflammation.

A high level of C-reactive protein in the blood indicated inflammation. There are a wide number of conditions that can cause it. It can be right from a minute infection to something as big as cancer.

A high level of this protein can also be a sign of inflammation in the arteries. And that can indicate a higher risk of a heart attack.

Although this test can show inflammatory conditions, it does not tell which part of the body is causing it. In means, that the CRP test is extremely nonspecific.

Why CRP Test Is Done?

If your health advisor suspects that you are suffering from an inflammatory disorder such as arthritis, infection, cancer, etc., then they may ask for C-reactive protein test results. This test shows if there is any high level of inflammation in the body. However, it does not tell what is causing the inflammation.

If you are already under some treatment regarding the inflammatory disorder, your doctor might ask for a test to monitor your response to the treatment. It is to check if the issue is properly managed and if the treatment is working well.

However, if the health practitioner is asking you to get a high-sensitivity C-reactive protein (hs-CRP) test done, then it may be related to your cardiovascular health. This test typically indicates a high risk of heart attack or stroke.

In short, the regular C-reactive test measures high levels of proteins and helps in uncovering different health conditions that can cause inflammation. Whereas the hs-CRP test measures the lower levels of protein (but still elevated) that can indicate the risk of heart disorders.

Also Read: Erythrocyte Sedimentation Rate Test (ESR Test) + Results Explained

When To Get CRP Blood Test Done?

Your doctor will recommend you this blood test to diagnose any inflammatory disease. The symptoms to get a CRP test done may include:

  • Unexplained exhaustion
  • Pain
  • Muscle stiffness, weakness, and soreness
  • Chills
  • Low-grade fever
  • Headache
  • Loss of appetite, indigestion, and nausea
  • Insomnia or difficulty in sleeping
  • Unexplained weight loss

A high level of C-reactive levels mostly indicates an acute bacterial infection.

Symptoms of acute infection include:

  • High fever
  • Uncontrollable sweating, shaking, or chills
  • Rapid heart rate
  • Difficulty in breathing
  • Rashes or hives
  • Uncontrollable vomiting, diarrhea, or retching
  • Parched lips, skin, or mouth
  • Lightheadedness or dizziness
  • Loss of consciousness
  • A severe headache, body ache, soreness, or stiffness

How To Get Tested?

CRT test is done only when the doctor prescribes it for diagnosing a health issue. You can either visit a diagnostic center for the test or check centers that can offer you CRP test at home facilities.

Before the CRP Test

There is no special preparation needed for the CRP test. You can eat normally throughout the day. The test can be performed at any time of the day irrespective of your meals.

During the CRP Test

Patient getting blood drawn for testing

A healthcare professional will draw blood from a vein in your arm during the test. It is usually inside of the elbow or on the backside of your hand.

First, they will clean the area with antiseptic liquid. Next, they will wrap an elastic band around your arm causing the veins to bulge slightly. Finally, they will insert a small needle into the vein to collect the sample.

After The CRP Test

There are near to no risks involved with the CRP test. You may experience normal bruising, swelling, or hematoma (a minor pool of blood under the skin) after drawing the blood.

Some people may feel lightheaded, dizzy, or even faint at times. That majorly depends on the person-to-person scenario. However, if you feel uncomfortable, talk to the health professional right away.

In very rare cases, you may face infection because of the needle puncture. Contact your doctor immediately if you come across such a situation.

Interpreting Results

The results of your CRP and hs-CRP test should be available within a day or two depending on the laboratory. It also depends on other tests performed along with the C-reactive protein test.

Also Read: 4 Blood Tests to Assess Your Heart Health

CRP Test Results

The test results for CRP are generally reported in milligrams per liter (mg/L) or milligrams per deciliter (mg/dL).

Depending on the CRP levels in your body, the health professional can narrow down the possible reason for inflammatory disorder.
Some of the most likely causes can be broken down as follows:

  • Less than 6 mg/L (0.3 mg/dL): CRP normal range (Healthy people)
  • 3 to 10 mg/L (0.3 to 1.0 mg/dL): Normal to moderate inflammation (seen in obese, pregnant, people who smoke, and those having health issues like diabetes or common cold)
  • 10 to 100 mg/L (1.0 to 10 mg/dL): Whole-body inflammation (can be due to autoimmune disease, pancreatitis, bronchitis, cancer, heart attack, etc.)
  • Over 100 mg/L (10 mg/dL): Marked as a whole-body inflammation (can be due to acute bacterial infections, systemic vasculitis, acute viral infections, major trauma, etc.)
  • Over 500 mg/L (50 mg/dL): Severe body-wide inflammation (can be due to severe bacterial infections)

hs-CRP Test Results

The results of a hs-CRP test can be classified as follows:

    • Lower than 1.0 mg/L: Low risk
    • 1.0 and 3.0 mg/L: Average risk
  • Above 3.0 mg/L: High risk

What To Do in Case of High CRP Levels?

Lowering the CRP levels does not guarantee to lower the risk of autoimmune disease or cardiovascular problems. The CRP levels are used as a factor among various others to analyze a person’s health. The test cannot be a stand-alone indicator of any diagnosis.

2015 study shows that when you eat a nutritious, balanced diet with lots of fruits, vegetables, and fibers, it may help to lower CRP concentration.

If you’re at high risk of a heart-related disorder, your doctor may suggest cholesterol-lowering medications. Including foods that contain vitamin C can also help in lowering CRP levels in people who have a high risk of heart problems.

Other than that, a 2017 research review suggests that adding probiotics to your everyday diet can also have a positive effect on lowering your CRP.

However, before you start including any of these suggestions in your everyday life, it is imperative to talk to a health professional. The high level of CRP may be due to several reasons. And so, there are various ways to control it too depending on the issue.

Also Read: Should you get a Lipid Profile Test? Answers to your Why

Final Takeaway

A CRP test is a blood test type to measure general inflammation in the body. It measures the level of C-reactive protein in the blood, which is produced in response to inflammation. Yet, the test cannot confirm the part of the body responsible for the inflammation. And the causes behind it can be various including infection, autoimmune disorder, or even cancer.

The hs-CRP test is a variation of this blood test used to predict the risk of a heart problem. The cardiovascular problem may include heart attack, stroke, etc.

A simple blood sample is all that is needed to get the test done. And you can either visit a laboratory or choose a diagnostic center that can provide blood tests at home option.


Are high CRP levels serious?

CRP levels of more than 350 milligrams per liter (mg/L) can always be a sign of a serious underlying medical condition. The most common reasons are severe infection, poorly controlled autoimmune disease, and severe tissue damage.

Is CRP test related to Covid?

According to a study, it is seen that there is a significant elevation in CRP levels (average 20 to 50 mg/L) in COVID‐19 cases. People who had severe COVID-19 infection had much far elevated CRP levels compared to the people with mild infections.

What foods increase CRP levels?

Typically a Western diet with high fats, sugar, refined grains, and sodium increases the CRP levels. Whereas, diets with high dietary fiber and rich in fruits and vegetables are linked with lower CRP levels.


by Dr. Neeraj Gujar

Dr. Neeraj Gujar has done his M.D. in Pathology from Government Medical College. He has worked at various organisations such as Breach Candy Hospital and Tata Memorial Hospital along with many other private organisations. During his working career, he realised the pressing need for exceptional quality diagnostic services. A diagnostic centre that can consistently give accurate results verified by a consultant doctor (M.D. Pathologist) on which your doctor can depend. This has been the founding principle of Primus Pathology and Diagnostics.

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