A liver function test (LFT or LF) is a type of blood test, in which the functioning of the liver is investigated. A doctor can examine the liver function by determining the amount of, for example, liver enzymes, proteins and bilirubin (bile colouring agent) in the blood.
Examination of the liver function is done to evaluate whether there is a liver disease and if so, what disease it is and what the cause is. Liver function test is also carried out to monitor the progress of an already demonstrated liver disease and as a check on the harmful effects of drugs or in case of alcohol abuse.
A standard liver function test includes several determinations. These all have to do with the various processes that are going on in the liver. The degree of increase and the relations between the various liver functions provide an indication towards the cause or type of liver disease. In order to make a final diagnosis, additional examination is often required. In most cases, this will be an ultrasound of the liver. The doctor may also decide to do a scan or liver puncture.
Blood is taken from a vein at the inside of the arm, usually in the fold of the elbow. After acquiring the sample, the blood is analyzed in a laboratory. The result may take several days and will be discussed with the patient by the doctor.