GI: Increased blood ammonia can most commonly result from decreased destruction of ammonia (liver disease) or by increased production of ammonia (GI bleed)

High ammonia levels in the blood, known as hyperammonemia, can be caused by various medical conditions. Ammonia is a waste product produced by the body during the breakdown of proteins, and it is normally converted into urea in the liver and excreted in urine. Elevated ammonia levels may indicate an issue with this process. Here are some common causes of high ammonia levels:

Liver Dysfunction: The liver plays a crucial role in converting ammonia to urea. Liver diseases such as cirrhosis, hepatitis, or liver failure can impair this conversion, leading to increased ammonia levels.

Urea Cycle Disorders: These are genetic disorders that affect the enzymes involved in the urea cycle, leading to an inability to properly convert ammonia. Examples include ornithine transcarbamylase deficiency (OTC deficiency) and citrullinemia.

Reye's Syndrome: This is a rare but serious condition that can occur in children after a viral infection, often associated with aspirin use during the infection. It can lead to liver and brain damage, causing an increase in ammonia levels.

Gastrointestinal Bleeding: Blood from the gastrointestinal tract contains proteins, and its entry into the body can increase ammonia levels. Conditions such as esophageal varices or gastrointestinal bleeding can contribute to hyperammonemia.

Kidney Dysfunction: Impaired kidney function can reduce the excretion of ammonia, leading to its accumulation in the blood.

Certain Medications: Drugs that affect the urea cycle or liver function, such as valproic acid (used for seizures) or certain chemotherapeutic agents, may contribute to hyperammonemia.

Inborn Errors of Metabolism: Some rare metabolic disorders, such as organic acidemias or fatty acid oxidation disorders, can lead to elevated ammonia levels.

Severe Dehydration: In cases of severe dehydration, reduced blood flow to the liver may impair its ability to process and convert ammonia.

Symptoms of hyperammonemia can include confusion, lethargy, nausea, vomiting, and, in severe cases, neurological symptoms. Prompt diagnosis and treatment of the underlying cause are essential. If someone is experiencing symptoms suggestive of high ammonia levels, they should seek medical attention for evaluation and appropriate management.

свернуть