Liver function tests (LFTs) are a group of blood tests that are used to assess the health of the liver. The liver is a vital organ that performs many important functions, including: Filtering blood: The liver filters blood and removes toxins and waste products. Making bile: The liver makes bile, which is a fluid that helps to digest fats. Storing glucose: The liver stores glucose, which is a type of sugar that provides energy for the body. Making proteins: The liver makes proteins that are important for blood clotting and other functions. LFTs can be used to diagnose liver damage, monitor the progression of liver disease, and assess the response to treatment. The most common LFTs include: Alanine transaminase (ALT): ALT is an enzyme that is found in the liver. High levels of ALT can indicate liver damage. Aspartate transaminase (AST): AST is another enzyme that is found in the liver. High levels of AST can also indicate liver damage. Albumin: Albumin is a protein that is made by the liver. Low levels of albumin can indicate liver damage. Bilirubin: Bilirubin is a waste product that is produced by the liver. High levels of bilirubin can indicate liver damage. Prothrombin time (PT): PT is a test that measures how long it takes for blood to clot. Prolonged PT can indicate liver damage. The results of LFTs can be affected by a number of factors, including: Medications: Some medications can affect the results of LFTs. Diet: Eating a high-fat diet can raise the levels of ALT and AST. Alcohol consumption: Drinking alcohol can damage the liver and raise the levels of ALT and AST. Illness: Other medical conditions, such as hepatitis and gallbladder disease, can also affect the results of LFTs.