Elevated AST and ALT levels

What liver diseases cause abnormal aminotransferase levels? I had blood test and my AST and ALT between twice the upper limits of normal. What does that mean? Have I some serious disease?

Hi! I had same problem. The cause of Elevated AST and ALT levels were fatty liver. Mild to moderate elevations of the liver enzymes are commonplace. The AST and ALT levels in such cases are usually between twice the upper limits of normal. The most common cause of mild to moderate elevations of these liver enzymes is fatty liver. The most frequent cause of fatty liver is alcohol abuse. Other causes of fatty liver include diabetes mellitus and obesity. Chronic hepatitis C is also becoming an important cause of mild to moderate liver enzyme elevations.