C-reactive protein FAQ

Your doctor may order a CRP test if you have symptoms of an infection, such as:

If your CRP level is intermediate or high, you should make the following changes to reduce your chances of heart disease:

Results that are greater than 10 milligrams per deciliter (mg/dL) are considered to be high. High levels usually mean you have some kind of inflammation in your body. This might be due to an infection, a serious injury, or an ongoing disease, like inflammatory bowel disease or rheumatoid arthritis. But the test won't tell you what is causing the inflammation. For that, the doctor would have to run other tests. You could also have a high level because you're in the second half of your pregnancy or you're using birth control pills. Moderate elevation If your CRP level is between 1 and 10 mg/dL, you could have:

The C-reactive protein (CRP) test measures the level of C-reactive protein in your blood. One study found that testing for CRP levels is a better indicator of cardiovascular disease (CVD) than the LDL test. But a CRP test is not a test for heart disease. It's a test for inflammation in the body. The test is also used for people who have autoimmune diseases like lupus and rheumatoid arthritis. These conditions also cause inflammation. A doctor might test someone with either condition to see if anti-inflammatory medication is working, though the CRP test cannot show where the inflammation is taking place in the body. Other things you can do with this test include:

If you have high cholesterol, you've probably been told to lower the LDL number from your blood test. LDL is the "bad cholesterol," the type that contributes to plaque that can clog your arteries. This can lead to a heart attack or stroke. But that's only part of the story. Research shows that a significant number of people who've had heart attacks have average or desirable LDL-C levels. L levels. So, many doctors use another test, called the C-reactive protein test, to help figure out who’s at risk. C-reactive protein (CRP) is produced by the liver. Its level rises when there's inflammation in your body. LDL cholesterol not only coats the walls of your arteries, but it also damages them. This damage causes inflammation that the body tries to heal by sending a "response team" of proteins called "acute phase reactants." CRP is one of these proteins.

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

A CRP test is sometimes confused with a high-sensitivity-(hs) CRP test. They both measure CRP, but they are used for different conditions. An hs-CRP test measures very tiny increases in your CRP levels. It is used to estimate your risk of heart disease .

By measuring the levels of c-reactive protein in your blood, a CRP test can tell your health care provider how much inflammation you have in your body. High CRP levels may mean you have an acute or chronic health condition, such as:

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This process usually takes less than five minutes.

Some medicines may affect your results. So, tell your provider about any supplements or medicines that you take, including magnesium and non-steroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen and aspirin. Don't stop taking any prescription medicines without talking with your provider first.

A c-reactive protein test measures the level of c-reactive protein (CRP) in a sample of your blood. Your liver makes CRP in response to inflammation.

In general, healthy people have very low amounts of CRP in their blood. A value of 0.8-1.0 milligrams per deciliter (mg/dL) or lower is thought to be a healthy amount. Any increases above normal may mean you have inflammation in your body. However, increases can also be linked to:

You may need this test if you have symptoms of a bacterial infection, such as:

To prepare for a C-reactive protein test, your healthcare team might ask you not to do hard exercise, such as intense weight training or a long run, before the test. Such activities can cause a sudden jump in the C-reactive protein level. Some medicines can affect the CRP level. Tell your healthcare professional about the medicines you take, including those you bought without a prescription. If your blood sample will be used for other tests, you may be told not to eat or drink for a while before the test. For example, if you're having an hs-CRP test to check for heart disease, you also might have a cholesterol test at the same time. Your healthcare professional tells you how to prepare for your test.

A C-reactive protein test requires a blood sample. To take a sample of your blood, a healthcare professional places a needle into a vein in your arm, usually at the bend of the elbow. The blood sample goes to a lab to be tested. You can return to your usual activities right away.

A C-reactive protein test may be done to: Check for infection. Help diagnose a chronic inflammatory disease such as rheumatoid arthritis or lupus. Learn your risk of heart disease. Learn your risk of a second heart attack.

It’s done with a simple blood test. It can be done at the same time your cholesterol is checked. Your chance of having heart disease is determined based on your test results: It's important to note that inflammation due to other things, like an infection, illness, or serious flare-up of arthritis , can also raise CRP levels. So before you get the CRP test, make sure to tell your doctor what other medical conditions you have.

It’s important for everyone to make these lifestyle changes to reduce their chance of having heart disease. It’s especially important if your CRP level is intermediate or high: Eat a heart-healthy diet . Get your high cholesterol down. Keep your weight where it should be. Exercise regularly. If you have diabetes or high blood pressure, manage it. If you smoke or use tobacco in another way, quit. If you drink alcohol, do so responsibly. Statins, the most commonly prescribed cholesterol-lowering drugs, may reduce your risk of heart disease if your CRP is high. Talk to your doctor about which treatments are best for you.

If you’re at moderate risk for heart disease, it may help your doctor figure out if you need more intensive treatment. Those at high risk should be treated aggressively, anyway. So CRP testing isn’t recommended for them. The more of these risk factors you have, the higher your risk of heart disease: A family history of heart disease High total cholesterol Low HDL cholesterol High blood pressure Being male or a post-menopausal woman You smoke cigarettes Uncontrolled diabetes or high blood pressure You don’t exercise You’re obese or overweight