What do LFTs measure? LFTs typically include the following tests: Alanine aminotransferase (ALT): An enzyme found primarily in the liver. High levels can indicate liver damage. Aspartate aminotransferase (AST): Another enzyme found in the liver and other tissues. High levels can also indicate liver damage, but can also be elevated due to muscle damage. Alkaline phosphatase (ALP): An enzyme found in the liver, bones, and other tissues. High levels can indicate liver or bone problems. Bilirubin (total and direct): A waste product from the breakdown of red blood cells. High levels can cause jaundice (yellowing of the skin and eyes) and indicate liver problems. Albumin: A protein made by the liver. Low levels can indicate liver disease or malnutrition. Total protein: Measures the total amount of protein in your blood. Why are LFTs performed? Doctors use LFTs to: Screen for liver disease: In people with risk factors or symptoms. Diagnose liver conditions: Such as hepatitis, cirrhosis, or fatty liver disease. Monitor the progression of liver disease. Monitor the effects of medications that can affect the liver.