Lab tests

CRP test | All you need to know 

CRP test

CRP test is often used to diagnose diseases, as well as to help track their progression.

It detects the Covid-19 infection. So its name became known to almost everyone. 

In this article, you’ll find everything you need to know about CRP analysis, its normal range, and what it means to increase it.


What is the CRP test?

CRP test is a simple blood test used to check the level of C-reactive protein in the blood. 

The liver makes C-reactive protein in response to inflammation anywhere in the body. 

An increase in C-reactive protein indicates inflammation without specifying its location. 

Inflammation occurs because of the body’s response to any disease or infection. 

Inflammation causes redness, swelling, and warmth at the injury site. 

Healthy individuals have low levels of CRP; Therefore, an increase in it often indicates a health problem that the body is facing.


When is CRP analysis required?

A doctor usually orders it to detect various conditions that cause inflammation and, subsequently, elevated CRP test levels. 

It is also used to monitor patients’ responses to a treatment plan. 

some of the major diseases that require performing this test include:

  • Bacterial infection like sepsis which is a life-threatening condition.
  • Fungal infections.
  • Inflammatory Bowel Syndrome.
  • Various autoimmune disorders, the most important of which are:
  • Lupus erythematosus.
  • Rheumatoid Arthritis.
  • Osteomyelitis.


A new study indicates that this test may be used to follow the health outcomes of patients with chronic obstructive pulmonary disease (COPD). 

The doctor may also order it besides other medical tests; To find out if a person is at risk of a heart attack or stroke.


What do high CRP test levels indicate?

High levels of CRP in the blood indicate inflammation; This inflammation may range from exposure to infection to cancer. 

Some doctors also believe that there is a link between a high level of CRP and an increased risk of heart attack or stroke. 

A high level may indicate the presence of inflammation in the arteries, thus the risk of a heart attack. 

A study was conducted on healthy men, with no prior history of heart disease. 

The study found that when the level of CRP was high, a person was three times more likely to have a heart attack compared to someone with a normal level of CRP.


CRP and COVID-19

crp and covid-19

Panic and fear have spread among people because of the Coronavirus; As it may lead to life-threatening complications. 

Some medical tests detect the severity and progression of the disease; Thus, this gives a greater chance of early treatment. 

This test is used with other tests to detect coronavirus infection. 

Scientists observed that the level of C-reactive protein in the blood increased from 20 to 50 mg/liter, in people infected with the Coronavirus. 

Its level is also higher in patients who are in an advanced stage of disease compared to those who have a mild infection.

One study indicated that the average C-reactive protein analysis is approximately 39.4 mg/liter in the presence of severe symptoms. 

The average in those with less severe symptoms reaches 18.8 mg/liter. 

Therefore, it gives a picture of the development of the disease and its severity with a group of other tests; This gives doctors more opportunity to treat the patient.


How do you prepare for a CRP analysis?

C-reactive protein is a simple blood test that doesn’t require special preparation. 

However, there are some situations to avoid in order to avoid making an unintentional error, such as:

  • Strenuous exercise, such as weight training and others, may help increase the level of CRP. So the doctor may ask the person to stop these sports before the test.
  • Don’t forget to tell the doctor about any medication you’re taking; Some medications affect the test results.
  • C-reactive protein test does not require fasting or abstinence from certain foods.


If done with other tests, the doctor may ask the person to fast for the other tests.


Complications of CRP test

There are no risks associated with this analysis, and complications do not exceed the possibility of a slight bruise or pain where the blood sample is drawn from a vein.


CRP test normal range

The test results are positive or negative: the test is negative if the result is in its normal range, meaning it is less than 10mg/L. 

The test is positive from 10 mg/L to more, this indicates the presence of inflammation in the body.

 Important note: CRP test normal range may vary slightly from laboratory to laboratory.


Standard CRP test and HS-CRP test

Is there a difference between the two? 

Both measure C-reactive protein, but the HS-CRP test is more sensitive than the other. 

HS-CRP can measure any slight increase within the normal range of a standard CRP test.


Why is the HS-CRP test used?

The HS-CRP test can determine susceptibility to cardiovascular disease and heart attack

A higher level of this test is associated with an increased risk of future heart attacks. 

When a person’s HS-CRP level is higher than normal, the risk of having another heart attack rises.

HS-CRP analysis is not required of everyone; however, it is performed on people who are at future risk of heart attacks by 10% to 20% within the next ten years.

The doctor evaluates the risk based on assessments that depend on several things, such as the health status, lifestyle of the individual, and family history. 

Here we come to the following question:


What do the results of the HS-CRP test indicate?

The results of this test mean:

Less than 1mg/L means a lower risk of heart disease.

1 to 3 mg/L means an average risk of heart disease.

Higher than 3mg/L indicates an increased risk of cardiovascular disease.

Blood cholesterol levels must be checked, to get a complete picture of factors that may increase the chance of developing heart disease. 

Analysis results may vary from time to time. 

Doctors usually order it twice, two weeks apart, to determine the risk of heart disease.


How much does the CRP test cost?

The CRP test price varies from one laboratory to another. 

It depends on the medical devices and equipment used.


In conclusion, the CRP analysis is a necessary medical test, that is crucial in diagnosing many diseases. 

This simple test shows the importance of medical tests to reveal the diagnosis of many diseases. 

Never hesitate to perform any medical tests that your doctor may ask you to; It may discover any danger to your health.


Read Also;

Triglycerides (TG): what you need to know

Translated by
Dr. Rana Lotfy
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