Hepatic transaminase tests such as alanine transaminase (ALT) and aspartate transaminase (AST) often are part of standard laboratory panels in asymptomatic outpatients, similar to screening tests for blood donors and for life insurance applicants.
http://www.aafp.org/afp/2005/0315/p1105.html
The range of possible etiologies at this level of transaminase elevation is broader (Table 15,6) and the tests less specific. It also is important to recall that patients with normal ALT and AST levels can have significant liver disease in the setting of chronic hepatocyte injury (e.g., cirrhosis, hepatitis C).
http://www.aafp.org/afp/2005/0315/p1105.html
The specific elevated liver enzymes most commonly found are: 1  Alanine transaminase (ALT) 2  Aspartate transaminase (AST)
http://www.mayoclinic.org/symptoms/elevated-liver-enzymes/basics/definition/SYM-20050830
But when the liver is injured, these enzymes are spilled into the blood stream. Among the most sensitive and widely used of these liver enzymes are the aminotransferases. They include GGT, aspartate aminotransferase (AST or SGOT) and alanine aminotransferase (ALT or SGPT). These enzymes are normally contained within liver cells. If the liver is injured, the liver cells spill the enzymes into blood, raising the enzyme levels in the blood and signaling the liver damage.
http://www.raysahelian.com/alt.html
However, very high elevations of the transaminases suggests severe liver damage, such as viral hepatitis, liver injury from lack of blood flow, or injury from drugs or toxins. Most disease processes cause ALT to rise higher than AST; AST levels double or triple that of ALT are consistent with alcoholic liver disease.
https://en.wikipedia.org/wiki/Elevated_transaminases
Although levels of ALT and AST can be extremely elevated (exceeding 2,000 U per L in cases of hepatocyte injury and necrosis related to drugs, toxins, ischemia, and hepatitis), elevations less than five times the upper limit of normal (i.e., about 250 U per L and below) are much more common in primary care medicine.
http://www.aafp.org/afp/2005/0315/p1105.html
What Are Normal AST and ALT Levels? The normal levels of AST and ALT vary from person to person and depend on your ​body mass index (BMI), or the ratio of your height and weight. A small amount of AST and ALT is normally in your blood, so it's really a large increase over your normal level that indicates a problem.
https://www.verywell.com/liver-enzymes-1759916
Aspartate aminotransferase, or AST, is found in the liver, but also the brain, pancreas, heart, skeletal muscle, kidneys, and lungs. Alanine aminotransferase, or ALT, is primarily found in the liver.
https://www.verywell.com/liver-enzymes-1759916
Elevated liver enzymes may indicate inflammation or damage to cells in the liver. Inflamed or injured liver cells leak higher than normal amounts of certain chemicals, including liver enzymes, into the bloodstream, which can result in elevated liver enzymes on blood tests. The specific elevated liver enzymes most commonly found are: Alanine transaminase (ALT) Aspartate transaminase (AST)
http://www.mayoclinic.org/symptoms/elevated-liver-enzymes/basics/definition/SYM-20050830
Elevated transaminases. In medicine, the presence of elevated transaminases, commonly the transaminases alanine transaminase (ALT) and aspartate transaminase (AST), may be an indicator of liver damage. Other terms employed include transaminasemia and transaminitis, although some sources consider the latter pathologically meaningless.
https://en.wikipedia.org/wiki/Elevated_transaminases
alt double of ast causes
ALT double of AST causes viral hepatitis, liver injury from lack of blood flow, or injury from drugs or toxins. Viral hepatitis, liver injury from lack of blood flow or injury from drugs or toxins are causes of ALT double of AST.