ALT, which stands for alanine transaminase, is an enzyme found mostly in the liver. When

liver cells are damaged, they release ALT into the bloodstream. An ALT test measures the

amount of ALT in the blood. High levels of ALT in the blood can indicate a liver problem,

even before you have signs of liver disease, such as jaundice, a condition that causes your

skin and eyes to turn yellow. An ALT blood test may be helpful in early detection of liver

disease.Normal levels of ALT (SGPT) ranges from about 7-56 units/liter of serum (the

liquid part of the blood), Normal levels of AST (SGOT) is about 5-40 units/liter of serum.

Elevated levels of AST and ALT may signify the level of liver damage in a person.