Ammonia is produced by some bacteria in intestine and during protein processing by cells of the body. Its a toxic product transports to liver, liver covert ammonia to urea and glutamine. This urea execrated through urine. Severe liver disease, kidney failure, Reye’s syndrome, decreased blood flow to liver and rare inherited urea cycle defects can create elevated ammonia levels in blood. This test ordered for newborns when they are irritable, vomiting, tired or have seizures during the first few days after birth. for children suspecting reye’s syndrome and adults experience sleepiness, disorientation, mental changes or lapse into a coma. This test can be performed in Heparin/EDTA plasma, do not use Ammonium Heparin