CRP (C-Reactive Protein) is a substance produced by the liver in response to inflammation. It is a marker that helps doctors assess the presence and intensity of inflammation in the body. Elevated levels of CRP can indicate various conditions, including infections, autoimmune diseases, and chronic inflammatory conditions. Doctors often measure CRP levels through a blood test. This test can help monitor the effectiveness of treatments or the progression of diseases. While CRP is a useful indicator, it is not specific to any one condition, so further testing may be needed to determine the underlying cause of inflammation.