Hyperammonemia

Hyperammonemia
Other names	Hyperammonaemia; High ammonia levels
Ammonia
Specialty	Endocrinology
Causes	Due to accumulation of argininosuccinate, citrulline, and arginine in the liver when the urea cycle is deficient.

Hyperammonemia, or high ammonia levels, is a metabolic disturbance characterised by an excess of ammonia in the blood. Severe hyperammonemia is a dangerous condition that may lead to brain injury 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. It is greatly exacerbated by common zinc deficiency, which raises ammonia levels further.^[1]