Patients with cirrhosis who have elevated blood ammonia should consider the possibility of hepatic encephalopathy. The cause of elevated blood ammonia is mainly due to decreased liver function, resulting in impaired metabolism of blood ammonia. In the case of hepatic encephalopathy in cirrhosis, the minor cases may include sleep disorder and reduced ability to calculate, while the severe cases may include unconsciousness or coma, delirium and so on. The treatment of hepatic encephalopathy requires a combination of treatment, starting with the identification of the cause of the elevated blood ammonia, such as whether there is gastrointestinal bleeding or electrolyte disturbance. In addition, it is also necessary to find out whether there is constipation, and some patients may have electrolyte disturbances caused by massive regression of ascites, which can also occur in hepatic encephalopathy.