My doctor ordered bloodwork to test my ammonia level...why would he order this? i have a tremor

Screening: They were likely screening for a metabolic disorder or liver disease.

Ammonia level: in some people with liver disease there are tremors. These can be due to an increase serum ammonia level due to the liver disease if so a medication can be given to decrease the ammonia level. he is probably jus wanting to be sure this is not the case.