BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuC-reactive proteinAcute phase reactants - CRPC-reactive protein (CRP) is produced by the liver. The level of CRP rises when there is inflammation in the body. It is one of a group of proteins, called acute phase reactants that go up in response to inflammation. The levels of acute phase reactants increase in response to certain inflammatory proteins called cytokines. These proteins are produced by white blood cells during inflammation.This article discusses the blood test done to measure the amount of CRP in your blood. How the Test is Performed A blood sample is needed. This is most often taken from a vein. The procedure is called a venipuncture.VenipunctureVenipuncture is the collection of blood from a vein. It is most often done for laboratory testing.ImageRead Article Now Book Mark Article How to Prepare for the Test No special steps are needed to prepare for this test. How the Test will Feel When the needle is inserted to draw blood, some people feel moderate pain. Others may feel only a prick or stinging sensation. Afterward, there may be some throbbing. Why the Test is Performed The CRP test is a general test to check for inflammation in the body. It is not a specific test. This means it can reveal that you have inflammation somewhere in your body, but it cannot pinpoint the exact location or reason. The CRP test is often done with the ESR (erythrocyte or sedimentation rate) test which also looks for inflammation.ESRESR stands for erythrocyte sedimentation rate. It is commonly called a "sed rate. "It is a test that indirectly measures the level of certain protei...ImageRead Article Now Book Mark Article You may have this test to:Check for flare-ups of inflammatory diseases such as rheumatoid arthritis, lupus, or vasculitis. Rheumatoid arthritisRheumatoid arthritis (RA) is a disease that leads to inflammation of the joints and surrounding tissues. It is a long-term disease. It can also aff...ImageRead Article Now Book Mark Article LupusSystemic lupus erythematosus (SLE) is an autoimmune disease. In this disease, the immune system of the body mistakenly attacks healthy tissue. It c...ImageRead Article Now Book Mark Article Determine if an anti-inflammatory medicine is working to treat a disease or condition.A more sensitive CRP test, called a high-sensitivity C-reactive protein (hs-CRP) assay, is available to determine a person's risk for heart disease. Normal Results Normal CRP values vary from lab to lab. The levels often increase slightly with age, female sex and in African Americans. The majority of healthy adults have levels less than 0.3 mg/dL.However, a low CRP level does not always mean that there is no inflammation present. Levels of CRP may not be increased in people with rheumatoid arthritis and lupus. The reason for this is unknown.Note: Normal value ranges may vary slightly among different laboratories. Talk to your health care provider about the meaning of your specific test results.The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens. What Abnormal Results Mean It is unclear if a minor rise of 0.3 to 1 mg/dL in CRP levels is a cause for concern. The hs-CRP is more precise and may be used to further understand these results.CRP levels from 1 mg/dL to 10 mg/dL are thought to be a moderate increase. CRP Levels greater than 10 mg/dL are considered a marked increase.A positive test means you have inflammation in the body. The cause of a high CRP cannot always be determined. Some include:Cancer CancerCancer is the uncontrolled growth of abnormal cells in the body. Cancerous cells are also called malignant cells.ImageRead Article Now Book Mark Article Heart attack Heart attackMost heart attacks are caused by a blood clot that blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. ...ImageRead Article Now Book Mark Article Infection Inflammatory bowel disease (IBD) Inflammatory bowel diseaseCrohn disease is a disease where parts of the digestive tract become inflamed. It most often involves the lower end of the small intestine and the be...ImageRead Article Now Book Mark Article Rheumatoid arthritis, lupus, and related diseases Rheumatic feverRheumatic feverRheumatic fever is a disease that may develop after an infection with group A streptococcus bacteria (such as strep throat or scarlet fever). It can...Read Article Now Book Mark Article According to the American Heart Association, results of the hs-CRP can be interpreted as follows:You are at low risk of developing cardiovascular disease if your hs-CRP level is lower than 1.0 mg/L. You are at average risk of developing cardiovascular disease if your levels are from 1.0 mg/L to 3.0 mg/L. You are at high risk for cardiovascular disease if your hs-CRP level is higher than 3.0 mg/L.Note: Positive CRP results also occur during the last half of pregnancy or with the use of birth control pills (oral contraceptives). Risks Risks associated with having blood drawn are slight, but may include:Excessive bleeding Fainting or feeling lightheaded FaintingFainting is a brief loss of consciousness due to a drop in blood flow to the brain. The episode most often lasts less than a couple of minutes and y...Read Article Now Book Mark Article Hematoma (blood accumulating under the skin) HematomaA bruise is an area of skin discoloration. A bruise occurs when small blood vessels break and leak their contents into the soft tissue beneath the s...ImageRead Article Now Book Mark Article Infection (a slight risk any time the skin is broken) Open ReferencesReferencesAnderson M, Cronstein B. Acute phase reactants. In: Firestein GS, McInnes IB, Koretzky GA, Mikuls TR, Neogi T, O'Dell JR, eds. Firestein & Kelley's Textbook of Rheumatology. 12th ed. Philadelphia, PA: Elsevier; 2025:chap 57.Dietzen DJ, Willrich MAV. Amino acids, peptides, and proteins. In: Rifai N, Chiu RWK, Young I, Burnham CD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. St Louis, MO: Elsevier; 2023:chap 31.Mora S, Libby P, Ridker PM. Primary prevention of cardiovascular disease. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 25.AllVideoImagesTogBlood test - illustration Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.Blood testillustrationBlood test - illustration Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.Blood testillustration Tests for C-reactive protein C-reactive proteinHLA-B27 antigenRelated Information Acute(Special Topic)Complement(Medical Test)Rheumatoid arthritis(Condition)Rheumatic fever(Condition)Cancer(Condition)Pulmonary tuberculosis(Condition)Community-acquired pneumonia in adults(Condition)Heart attack(Condition)Systemic lupus erythematosus(Condition)Rheumatoid arthritis - InDepth(In-Depth)Pneumonia - InDepth(In-Depth)Heart attack and acute coronary syndrome - InDepth(In-Depth) Review Date: 1/28/2025 Reviewed By: Diane M. Horowitz, MD, Rheumatology and Internal Medicine, Northwell Health, Great Neck, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. © 1997- All rights reserved. A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.Content is best viewed in IE9 or above, Firefox and Google Chrome browser.
C-reactive proteinAcute phase reactants - CRPC-reactive protein (CRP) is produced by the liver. The level of CRP rises when there is inflammation in the body. It is one of a group of proteins, called acute phase reactants that go up in response to inflammation. The levels of acute phase reactants increase in response to certain inflammatory proteins called cytokines. These proteins are produced by white blood cells during inflammation.This article discusses the blood test done to measure the amount of CRP in your blood. How the Test is Performed A blood sample is needed. This is most often taken from a vein. The procedure is called a venipuncture.VenipunctureVenipuncture is the collection of blood from a vein. It is most often done for laboratory testing.ImageRead Article Now Book Mark Article How to Prepare for the Test No special steps are needed to prepare for this test. How the Test will Feel When the needle is inserted to draw blood, some people feel moderate pain. Others may feel only a prick or stinging sensation. Afterward, there may be some throbbing. Why the Test is Performed The CRP test is a general test to check for inflammation in the body. It is not a specific test. This means it can reveal that you have inflammation somewhere in your body, but it cannot pinpoint the exact location or reason. The CRP test is often done with the ESR (erythrocyte or sedimentation rate) test which also looks for inflammation.ESRESR stands for erythrocyte sedimentation rate. It is commonly called a "sed rate. "It is a test that indirectly measures the level of certain protei...ImageRead Article Now Book Mark Article You may have this test to:Check for flare-ups of inflammatory diseases such as rheumatoid arthritis, lupus, or vasculitis. Rheumatoid arthritisRheumatoid arthritis (RA) is a disease that leads to inflammation of the joints and surrounding tissues. It is a long-term disease. It can also aff...ImageRead Article Now Book Mark Article LupusSystemic lupus erythematosus (SLE) is an autoimmune disease. In this disease, the immune system of the body mistakenly attacks healthy tissue. It c...ImageRead Article Now Book Mark Article Determine if an anti-inflammatory medicine is working to treat a disease or condition.A more sensitive CRP test, called a high-sensitivity C-reactive protein (hs-CRP) assay, is available to determine a person's risk for heart disease. Normal Results Normal CRP values vary from lab to lab. The levels often increase slightly with age, female sex and in African Americans. The majority of healthy adults have levels less than 0.3 mg/dL.However, a low CRP level does not always mean that there is no inflammation present. Levels of CRP may not be increased in people with rheumatoid arthritis and lupus. The reason for this is unknown.Note: Normal value ranges may vary slightly among different laboratories. Talk to your health care provider about the meaning of your specific test results.The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens. What Abnormal Results Mean It is unclear if a minor rise of 0.3 to 1 mg/dL in CRP levels is a cause for concern. The hs-CRP is more precise and may be used to further understand these results.CRP levels from 1 mg/dL to 10 mg/dL are thought to be a moderate increase. CRP Levels greater than 10 mg/dL are considered a marked increase.A positive test means you have inflammation in the body. The cause of a high CRP cannot always be determined. Some include:Cancer CancerCancer is the uncontrolled growth of abnormal cells in the body. Cancerous cells are also called malignant cells.ImageRead Article Now Book Mark Article Heart attack Heart attackMost heart attacks are caused by a blood clot that blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. ...ImageRead Article Now Book Mark Article Infection Inflammatory bowel disease (IBD) Inflammatory bowel diseaseCrohn disease is a disease where parts of the digestive tract become inflamed. It most often involves the lower end of the small intestine and the be...ImageRead Article Now Book Mark Article Rheumatoid arthritis, lupus, and related diseases Rheumatic feverRheumatic feverRheumatic fever is a disease that may develop after an infection with group A streptococcus bacteria (such as strep throat or scarlet fever). It can...Read Article Now Book Mark Article According to the American Heart Association, results of the hs-CRP can be interpreted as follows:You are at low risk of developing cardiovascular disease if your hs-CRP level is lower than 1.0 mg/L. You are at average risk of developing cardiovascular disease if your levels are from 1.0 mg/L to 3.0 mg/L. You are at high risk for cardiovascular disease if your hs-CRP level is higher than 3.0 mg/L.Note: Positive CRP results also occur during the last half of pregnancy or with the use of birth control pills (oral contraceptives). Risks Risks associated with having blood drawn are slight, but may include:Excessive bleeding Fainting or feeling lightheaded FaintingFainting is a brief loss of consciousness due to a drop in blood flow to the brain. The episode most often lasts less than a couple of minutes and y...Read Article Now Book Mark Article Hematoma (blood accumulating under the skin) HematomaA bruise is an area of skin discoloration. A bruise occurs when small blood vessels break and leak their contents into the soft tissue beneath the s...ImageRead Article Now Book Mark Article Infection (a slight risk any time the skin is broken) Open ReferencesReferencesAnderson M, Cronstein B. Acute phase reactants. In: Firestein GS, McInnes IB, Koretzky GA, Mikuls TR, Neogi T, O'Dell JR, eds. Firestein & Kelley's Textbook of Rheumatology. 12th ed. Philadelphia, PA: Elsevier; 2025:chap 57.Dietzen DJ, Willrich MAV. Amino acids, peptides, and proteins. In: Rifai N, Chiu RWK, Young I, Burnham CD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. St Louis, MO: Elsevier; 2023:chap 31.Mora S, Libby P, Ridker PM. Primary prevention of cardiovascular disease. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 25.
