I have been itchy all over (no rash) for the past month. recently had iron studies, hepatitis testing etc and all looked normal. my pcp ordered tests for ammonia. i do have nafld. does an ammonia test make sense as something that would cause itching?

Chronic liver disease is one of various disorders that can cause itching without a rash. Look into elevated serum histamine levels as a cause. While chronic liver&kidney disease can cause itching, I'd consider a high ammonia level to only be seen in advanced cases. I've not seen itching listed as a typical symptom of high ammonia levels. I usually refer these patients to dermatology for testing