American Board of Pathology (ABPath) Practice Test

The condition characterized by confusion due to elevated levels of ammonia is hepatic encephalopathy. This phenomenon occurs when the liver is unable to adequately detoxify substances in the blood, particularly ammonia, which is a byproduct of protein metabolism. In hepatic encephalopathy, high ammonia levels affect the brain and can lead to various neurological symptoms, with confusion being one of the most prominent.

The underlying liver dysfunction, which may stem from conditions such as cirrhosis, results in reduced clearance of ammonia. As a consequence, ammonia accumulates in the bloodstream and can cross the blood-brain barrier, resulting in neurological impairment.

In contrast, cirrhosis is a liver condition that can lead to hepatic encephalopathy, but it is not directly characterized by confusion itself. Ascites is the accumulation of fluid in the abdominal cavity and is often a complication of liver diseases like cirrhosis, but does not involve confusion or neurological symptoms directly. Liver cancer may contribute to liver dysfunction and subsequently hepatic encephalopathy, but the confusion is a result of the encephalopathy rather than the cancer itself. Therefore, the most direct answer to the question about the condition that causes confusion due to elevated ammonia levels is hepatic encephalopathy.