Liver Function Tests: So Mysterious, Yet So Important

The liver is the second largest organ in the humanalbumin test and the serum globulin test.
body (only the skin is bigger). The liver is also oneSerum albumin is the main protein in blood plasma.
of the most important organs, because itA decrease in the serum albumin level may
performs dozens of tasks that are critical toindicate chronic liver disease. Serum albumin can
human health. Since most liver diseases causealso be decreased in other conditions like kidney
only mild symptoms in the early stages, it's vitaldisorders and malnutrition.
to detect these diseases early.The serum globulin test measures the three
Basically, liver function tests, which are alsotypes of globulins (globulins contain most of the
routinely called "LFTs," assess the overall healthantibodies of the blood): alpha, beta and gamma.
and the anatomical integrity of liver. LFTs includeThe liver synthesizes the first two and the cells
measurements of albumin, various liver enzymes,of the immune system synthesize the gamma
bilirubin, cholesterol and total protein. All of theseglobulin. In liver disorders, the alpha and the beta
tests can be performed at the same time.globulin are decreased and the gamma globulin
Liver function tests are generally divided into fourlevels are significantly increased. The normal
categories.albumin globulin ratio is reversed.
1) Tests based on the detoxification and4) Other tests might include ultrasonography and
excretory functions. The serum bilirubin test isbiopsy. Ultrasonography is done as the first test
typical. Bilirubin is an orange-colored substance infor diagnosing obstructive jaundice. It is also done
bile produced by the breakdown of red blood cells.in cases of gall stone disease and detecting lesions
When bilirubin levels are high, a condition calledin the liver. Along with Doppler, it is used to
jaundice occurs. Too much bilirubin is usually dueassess the condition of the blood vessels.
to increased destruction of red blood cellsBiopsy is done through the skin (sometimes with
(hemolysis) or because the liver can no longerthe ultrasonographic guidance) in cases of liver
remove bilirubin in a timely manner.disease of uncertain cause. Biopsy can also
2) Tests that detect damage to the liveruncover suspected cancers, enlarged liver and
structure. There are a number of enzymes in theenlarged spleen.
liver. Elevated liver enzymes indicate that there isIn summary, liver function tests evaluate a wide
damage to the liver cells, or that there is anrange of normal tasks performed by the liver. But
obstruction to bile flow.a reliable diagnosis also depends on a complete
3) Tests based on bio-synthetic functions. Thesehistory and complete physical examination in
liver function tests typically include the serumaddition to the test themselves.