ammoniemia (Wikipedia)
Ammonia lone electron pair.svg
Classification and external resources
Specialty endocrinology
ICD-10 E72.2
ICD-9-CM 270.6
DiseasesDB 20468
eMedicine neuro/162 ped/1057
MeSH D022124

Hyperammonemia (or hyperammonaemia) is a metabolic disturbance characterised by an excess of ammonia in the blood. It is a dangerous condition that may lead to encephalopathy and death. It may be primary or secondary.

Ammonia is a substance that contains nitrogen. It is a product of the catabolism of protein. It is converted to the less toxic substance urea prior to excretion in urine by the kidneys. The metabolic pathways that synthesize urea involve reactions that start in the mitochondria and then move into the cytosol. The process is known as the urea cycle, which comprises several enzymes acting in sequence.