Typically, an AST blood test, or aspartate transaminase test, is used to test for liver damage or inflammation. This test does not tell the physician that it is in fact your liver, just that the problem could be your liver.
Other problems that could cause high AST
There are other organs that can be damaged and result in an increase in AST in your blood. Heavy exercise, muscle injury, heart problems, issues with skeletal muscles, pancreatitis and heart attack can also register a high AST level in your blood. To prevent an incorrect diagnosis, your doctor will perform other tests to determine whether it is in fact your liver.
How AST blood test is used
The AST blood test is typically used with the ALT blood test. AST is the most important test of the two, but when they are compared can determine between causes of liver damage. This is called the AST/ALT ratio.
AST levels are also compared to the ALP, bilirubin, and total protein levels to help find the true cause of the liver problem. It can also be used to test for potential toxicity in people who ar taking medication that could cause liver damage.
What your doctor should know
There are some things that may affect your AST levels. AST levels may be decreased by pregnancy, while increases in AST may be caused by injections and heavy exercise. Certain medications can increase AST levels in the blood and can also cause liver damage.
Let your doctor know about any over-the-counter medications you are on, as well as natural vitamins and supplements you are taking or have taken recently.