What is a CRP (C-reactive Protein) test?

A C-Reactive Protein (CRP) test is one that is used to measure the levels of C-reactive protein which is made by the liver that flows in the blood. It is due to inflammation, that this protein gets released into the bloodstream by the liver.

What is inflammation?

Inflammation is a general process through which the body’s white blood cells (WBCs) and its process of protecting the body against infections from foreign substances such as bacteria and viruses. Inflammation is the body’s defense mechanism against harmful bacteria and viruses and also plays a major role in the healing process. It can also be called a biological response. 

Certain cells begin an inflammatory response to trap bacteria and other offending agents or start healing injured tissue. The result can be pain, swelling, bruising or redness. 

What diseases are related to inflammation?

The problems related to inflammation are asthma, tuberculosis, arthritis, periodontitis, rheumatoid arthritis, sinusitis, heart problems, cancer, alzheimer’s, and in some cases, even diabetes. 

Does inflammation cause pain?

Unfortunately, inflammation can cause all sorts of pains such as sharp pain, throbbing pain, constant pain, pinching pain, shooting pain, and stabbing pain. In fact, biochemical processes can also induce pain as they affect how nerves act. 

Why is a C-Reactive Protein (CRP) test done?

A CRP test is done to look for underlying diseases and problems. Inflammation is just a reaction which causes uncomfortable and unexplained pains. Hence, the CRP test may be useful for various screening tests.

Infection:

An infection is again a response by the body due to some bacteria or virus. This includes pneumonia, sepsis, skin infection, etc. 

Chronic Inflammatory Disease:

In this type, inflammation remains for a longer time period. It can last months and even years and can cause conditions such as: 

1. Cancer
2. Heart disease
3. Diabetes
4. Asthma 
5. Alziehmer’s disease 
6. Lupus
7. Rheumatoid Arthritis
8. Inflammatory Bowel disease

What does a C-Reactive Protein (CRP) test detect?

The CRP test is a general test for checking inflammation in the body. However, it is used to detect if someone is having symptoms that are related to an inflammatory or non-inflammatory condition. The CRP test helps in determining several other conditions such as:

1. Allergy 
2. Asthma 
3. Bacterial infection
4. Bronchitis 
5. Cancer
6. Celiac disease
7. Chronic obstructive pulmonary disease
8. Diabetes
9. Heart issues
10. Pneumonia
11. Viral infections
12. High blood pressure (hypertension)

According to several studies, high levels of inflammation is also related to fatigue.

CRP test is sometimes also used to predict the progression of COVID-19. 

How is the C-reactive protein (CRP) test performed? 

A CRP test is a blood test that does not require fasting. One can resume normal and daily activities, however, there may be some swelling and redness around the injection site. 

This test is usually performed along with the ESR blood test, AKA Erythrocyte Sedimentation Rate which is primarily a blood test performed to check inflammatory activities in the body. It measures how quickly erythrocytes (red blood cells) settle at the bottom of the testing tube, which indicates the level of inflammation in the body.

What does the CRP test results mean?

The CRP test is measured in milligrams per liter (mg/L) or milligrams per deciliter (mg/dL). The CRP levels can either be high or low depending upon the levels of inflammation in the body. Based on the levels, the doctor narrows down the possible causes of this inflammation which leads to various illnesses. 

Levels in the CRP test results: 

1. Healthy range/ Normal CRP values: Less than 6 mg/l or 0.3 mg/dL. This value is seen in healthy people. 
2. Normal to moderate inflammation: 3 to 10 mg/l or 0.3 to 1.0 mg/dL. This value is mainly seen in people who are pregnant, obese, people who smoke, have diabetes, etc. This range refers to moderate inflammation. 
3. Whole body inflammation: 10 to 100 mg/l or 1.0 to 10 mg/dL. There is inflammation in the whole body due to autoimmune diseases, bronchitis, pancreatitis, heart attack, or cancer.
4. Marked whole-body inflammation: Over 100 mg/l or 10 mg/dL. This range of inflammation is due to acute bacterial infections, acute viral infections, systemic vasculitis, or major trauma.
5. Severe body-wide inflammation: Over 500 mg/l or 50 mg/dL. This is the widest range of inflammation due to severe bacterial infections. 

How much CRP level is dangerous in COVID-19? 

20-50 mg/l is the level that is considered highly dangerous in COVID patients. Reports suggest, patients with severe disease courses had a far elevated level of CRP than mild or non‐severe patients. 

CRP normal value is usually less than 6 mg/l and it is considered to be safe in the case of inflammation. If in any case the values are between 10-100 mg/l, immediate medical assistance is required. 

If you or anyone you know is facing issues such as unexplained pains and pain in the joints or muscles, book a blood testing lab as soon as possible.