Answer:
ALT and AST can be elevated in many diseases, but are indicators of the health of the liver. If they are both elevated then there is something going on with the liver, but without more information, or without knowing their numbers I wouldn't be able to give a reliable diagnosis.
Some of the causes of elevated ALT and AST are: alcoholism, hepatitis, liver cirrhosis, liver cancer, and some blood disorders, but there are many more.