Liver function tests are a selection of blood tests undertaken in order to check information relating to the condition of an individual's liver. It may be abbreviated as LFT, and is otherwise known by names such as liver function series (LFS) or liver panel. There are seven tests in the standard panel, and one sample of blood can be used to complete all of them. Their main focus is on lowered or elevated liver enzymes of various sorts.

Some liver conditions begin with no symptoms, or perhaps mild symptoms. Taking LFTs may be useful in diagnosis of a disease that would not have been suspected based on symptoms. Various results can indicate potential liver disease, and in some cases even be useful in distinguishing between different forms. The level to which the liver has been damaged may also be able to be found out. Additionally, liver function tests can be performed to track how the patient is responding to treatment.

Alanine transaminase (ALT)

This enzyme is generally found in hepatocytes, which are liver cells. However, when damage to those occur, ALT can enter into the patient's blood. Acute liver damage is where ALT can see significant elevation. Viral hepatitis is one such condition.

Alkaline phosphatase (ALP)

The liver's biliary ducts are where ALP is normally found. When large bile duct obstruction (or one of other certain conditions) takes place its levels in the blood can become higher.

Aspartate transaminase (AST)

Aspartate transaminase is elevated in cases of acute liver damage. On the other hand, it is not particular to the liver. A biomarker in evaluating heart function is another use of AST.

Direct bilirubin (DBIL)

This particular measurement can be looked at along with total bilirubin. Elevation of DBIL suggests something such as gallstones causing a bile duct obstruction, or possibly cancer. Normal levels of DBIL where the TBIL is raised means that unconjugated bilirubin is the type with higher levels. Cirrhosis, viral hepatitis infection, and hemolysis are several possibilities in this situation.

Total bilirubin (TBIL)

An increased level of TBIL can point to various medical issues. This liver function change could be due to increased production, decreased metabolism, or bile duct obstruction.

Albumin (Alb)

Chronic liver diseases such as cirrhosis can lead to lowered levels of albumin. This result is also possible should excessive amounts of it leave the body in urine, which can occur in nephrotic syndrome. Additionally, low levels might be seen if there is protein catabolism or poor nutrition.

Gamma glutamyl transpeptidase (GGT)

This enzyme is elevated in both acute and chronic alcohol toxicity. Moreover, it can be raised even where there is only minor -- even subclinical -- dysfunction of the liver. It is more sensitive, in this way, than ALP, compared with which it is also more particular to the liver.