Acute phase proteins are a group of proteins whose levels increase or decrease in response to inflammation or injury. They are produced mainly by the liver and play a crucial role in the body's immune response. Common examples include C-reactive protein (CRP) and fibrinogen, which help to identify and manage infections or tissue damage. These proteins act as markers for inflammation and can be measured through blood tests. Elevated levels of acute phase proteins can indicate various conditions, such as infections, autoimmune diseases, or chronic inflammatory disorders. Monitoring these proteins helps healthcare providers assess a patient's health status and response to treatment.