Clinical and laboratory features:
(1) reduced level of consciousness
(2) elevated plasma ammonia concentration
Liver disease:
(1) cirrhosis with portal hypertension
(2) other causes of portal hypertension
(3) Reye's syndrome
Inherited metabolic disorders (especially the urea cycle enzyme defects):
(1) argininosuccinic acid lyase deficiency (ASAL)
(2) lysinuric protein intolerance (LPI)
(3) hyperammonemia-hyperornithinemia-homocitrullinemia syndrome (HHH)
(4) citrullinemia (argininosuccinic acid synthetase or ASA deficiency)
(5) argininemia (arginase deficiency)
(6) carbamylphosphate synthetase I or N-acetylglutamate synthetase (CPS/NAGS)
(7) organic acidopathies
Oncologic conditions:
(1) multiple myeloma and other hematopoietic conditions
(2) cytoreductive chemotherapy
(3) bone marrow transplant
Drug-related:
(1) valproic acid
(2) asparaginase (? effect on aspartate)
Infection related:
(1) urinary tract infection
(2) ureterosigmoidostomy-related rectocolitis
Other:
(1) transient hyperammonemia of the newborn (TNH, THAN)
(2) excessive intake of essential amino acids
