The normal range for C-reactive protein, or CRP, is less than 1.0 milligram per deciliter or less than 10 milligrams per liter, reports WebMD. The CRP blood test measures the amount of C-reactive protein in the blood. Doctors use CRP testing to judge the level of inflammation in the body.
An elevated CRP level generally indicates long-term disease or infection, notes WebMD. Doctors use the test to monitor disease progression and treatment efficacy for conditions such as lupus, lymphoma, rheumatoid arthritis, giant cell arteritis or inflammatory bowel disease. Doctors may also order CRP blood testing to check for postsurgical infections.