The normal range of CRP (C-Reactive Protein) is less than 1 milligram per deciliter of blood as stated by WebMD. The ranges of CRP testing and values vary from lab to lab. In addition, sudden or severe inflammation can increase CRP levels while certain medicines can decrease CRP levels.
High levels of CRP can indicate inflammation or a variety of long-term diseases, states WebMD. Medical professionals often perform CRP tests to check for infection after surgery. CRP tests can also be used to check for diseases that cause inflammation, such as lymphoma, lupus, inflammatory bowel disease and osteomyelitis. CRP testing may be impossible or non-beneficial for pregnant or overweight individuals, as well as those who just exercised or have an infection.