| Reye syndrome |
| Gastrointestinal bleeding |
| Renal disease |
| Urinary tract infection with a urease-producing organism (eg, Proteus mirabilis) |
| Ureterosigmoidostomy |
| Shock |
| Severe muscle exertion/heavy exercise |
| Cigarette smoking |
| Transient hyperammonemia in newborns |
| Certain inborn errors of metabolism (urea cycle defects and organic acidemia) |
| Any cause of portosystemic shunting of blood |
| Parenteral nutrition |
| After high-dose chemotherapy |
| Drugs such as: |
| Valproic acid |
| Barbiturates |
| Narcotics |
| Diuretics |
| Alcohol |
| Salicylate intoxication |
| Systemic Mycoplasma hominis or Ureasplasma spp infection in lung transplant recipients |
