C-reactive protein (CRP) by nephelometry

Why This Test Might Be Ordered

Your doctor may order a CRP test to monitor conditions like arthritis, infections, or heart disease. It can also help check for inflammation after surgery or injury, or to screen for risks before procedures. Some doctors use it to track how well treatments are working for conditions like lupus or rheumatoid arthritis.

What to Expect Before the Test

No special preparation is needed for this blood test. You may be asked to fast for 8–12 hours before your blood is drawn, but your doctor will let you know if fasting is required. Avoid strenuous activity or taking anti-inflammatory medications for 24 hours before testing, as they may affect results.

What Happens During the Test

A healthcare provider will insert a small needle into a vein in your arm to draw a blood sample. You may feel a brief pinch, but the procedure usually takes just a few minutes. The blood is then sent to a lab for analysis using a nephelometry method, which measures how much CRP is present in your serum.

What the Results Mean

CRP levels vary depending on your health and medical history. Higher than expected levels may indicate inflammation, infection, or other health concerns. Your doctor will interpret the results in the context of your symptoms and medical history to guide next steps.