Hepatic encephalopathy
（重定向自Hepatic coma）
![](/Images/godic/202501/17/Alzheimer_type_II_astrocyte_high_mag3433.jpg")
![Ball and stick model of ammonia; one nitrogen atom with three hydrogen atoms. Accumulation of ammonia in the bloodstream is associated with hepatic encephalopathy.](/Images/godic/202501/17/Ammonia-3D-balls-A3433.png")
![Micrograph of Alzheimer type II astrocytes, as may be seen in hepatic encephalopathy.](/Images/godic/202501/17/Alzheimer_type_II_astrocyte_high_mag_cropped3434.jpg")
![Micrograph showing liver cirrhosis, a condition that often precedes hepatic encephalopathy. Trichrome stain.](/Images/godic/202501/17/Cirrhosis_high_mag3434.jpg")
Hepatic encephalopathy (HE) is the occurrence of confusion, altered level of consciousness, and coma as a result of liver failure. In the advanced stages it is called hepatic coma or coma hepaticum. It may ultimately lead to death.
It is caused by accumulation in the bloodstream of toxic substances that are normally removed by the liver. The diagnosis of hepatic encephalopathy requires the presence of impaired liver function and the exclusion of an alternative explanation for the symptoms. Blood tests (ammonia levels) may assist in the diagnosis. Attacks are often caused by another problem, such as infection or constipation.