Ammonia poisoning caused by ammonia metabolism disorder is an important pathogenesis of hepatic encephalopathy. When the liver is damaged, liver function is reduced or even liver failure, the metabolizing ability of the liver to ammonia is obviously reduced, resulting in ammonia entering the blood circulation and causing ammonia poisoning. Ammonia is toxic, can pass the blood-brain barrier, interfere with the tricarboxylic acid cycle, so that the energy supply of brain cells is insufficient, inhibit brain function, lead to cell swelling, and induce cerebral edema, in addition, ammonia can directly interfere with neuroelectrophysiological activities. Since ammonia toxicity is an important pathogenesis of hepatic encephalopathy, treatment consists of promoting ammonia metabolism in the body. Commonly used drugs include L-ornithine-L-aspartic acid and ornithine-alpha-ketoglutarate. Severe hepatic encephalopathy can lead to a rapid entry into a coma, which may result in death if not resuscitated in time. Hepatic encephalopathy should be treated promptly by a medical professional to avoid self-diagnosis and treatment, which may lead to delays.