Cells all across the body particularly those in the intestines liver and kidneys create ammonia (NH3). The liver converts the majority of the ammonia created by the body into urea. Although urea is a waste product as well it is considerably less harmful than ammonia. The brain is highly hazardous to ammonia. It may result in fuzziness fatigue and occasionally coma. If your doctor suspects you have a condition that could result in a dangerous ammonia buildup they may perform this test on you. Hepatic encephalopathy a serious liver disorder is most frequently diagnosed and tracked using it.