The human liver is an organ with many complex functions. Most of what the liver does is accomplished through the production of enzymes: compounds that act as catalysts for chemical reactions necessary for bodily health. Liver enzymes are normally found in the blood at certain levels. Elevated liver enzymes are usually an indication that something is wrong with the liver. Specific enzymes, levels of elevation, and ratios to the elevation of other enzymes can tell physicians a lot about how healthy the liver is and what may be wrong with it. Other diagnostic procedures are normally used as a follow up to blood tests to identify visible signs of problems or those that appear in a biopsy.
A liver function test is a collection of blood tests that provide information about liver functioning. Commonly grouped together are tests for liver transaminases in the blood, along with albumin (a blood protein), bilirubin (a breakdown product normally excreted in bile), and others.
Depending on whom one asks, tests for aminases may or may not be considered liver function tests. These liver enzymes when elevated (particularly aspartate transaminase –
The most important follow-
Another diagnostic procedure that may be used, especially to identify cancer or to verify the presence of infection, is a liver biopsy. In this test, a needle is used to extract a small sample of liver tissue, which is then subjected to laboratory testing.
If blood is drawn for a liver enzyme test within a certain range of time after drinking substantial amounts of alcohol, elevated enzymes may be found that do not necessarily indicate liver disease but rather a reaction to the alcohol. For this reason, the test may need to be repeated after cessation of drinking in order to correctly indicate possible damage to the liver. Of course, alcohol consumption is also a primary cause
of liver disease.
Liver diseases that can be indicated by elevated enzymes include (without limitation) fatty liver, hepatitis (both infectious and non-
These liver diseases vary widely in how serious they are. Fatty liver is a condition usually without overt symptoms that does not significantly impact liver functioning. However, it can also be an early sign of more serious illnesses. Hepatitis is a swelling of the liver can be due to viral infections, alcohol abuse, or other causes. It may be acute or chronic, and may provoke different levels of concern. Cirrhosis of the liver is a progressive disease that can result in complete liver failure and death if the progress is not arrested. Cancer is of course always of serious concern.
In many cases, early identification of the disease is the key to successful treatment. The damage to the liver is often irreversible if not stopped. Since many of these diseases have no overt symptoms in their early stages, liver enzyme tests can be very important in providing an early diagnosis.