The phrase "liver function tests" or "LFTs" is commonly used by patients and physicians. Many patients and physicians use the term to describe the AST and ALT. However, this is not correct--the AST and ALT do not measure the function of the liver.
The true function of the liver is actually best measured by the PT, INR and albumin. Therefore, if you are getting a PT, INR or albumin, these tests can determine how the liver is "functioning."