C-reactive protein (CRP) by nephelometry

What Is C-Reactive Protein?

C-reactive protein (CRP) is a marker that your body produces when it detects inflammation. It’s often measured in blood tests to help diagnose or track conditions like infections, heart disease, or autoimmune disorders. CRP doesn’t directly indicate the cause of inflammation but can signal when your body is responding to injury, illness, or stress.

Why Might You Need This Test?

Your healthcare provider may order a CRP test if you have symptoms of inflammation, such as fever, pain, or swelling, or if you’re at risk for conditions like heart disease, arthritis, or infections. It can also be used to monitor chronic conditions like rheumatoid arthritis or to check for signs of infection after surgery or illness.

How Is the Test Performed?

A small amount of blood is drawn from a vein, usually in your arm, and sent to a lab. The lab uses a specialized technique called nephelometry to measure CRP levels in your blood sample.

What Do the Results Mean?

Results are typically reported in milligrams per deciliter (mg/dL). Higher than normal levels may indicate inflammation, but they don’t always point to a specific cause. Your doctor will interpret the results in the context of your symptoms and medical history.