When the liver has been damaged by cirrhosis, it may not be able to filter poisons from the bloodstream, especially substances in the blood produced by bacteria in the large intestine. As a result, these substances (which include ammonia) may build up in the bloodstream and cause problems in your brain called encephalopathy. High ammonia levels are a sign of encephalopathy.

Symptoms of encephalopathy may include:

• Irritability.
• Depression.
• Drowsiness.
• Difficulty with word-finding.
• Poor short-term memory.
• Poor concentration.
• Confusion and disorientation.
• Insomnia.
• Coma.

Encephalopathy is most likely to occur in people who have high blood pressure in the portal vein system (portal hypertension). However, it may also occur in people with severe acute liver damage who do not have portal hypertension. Certain procedures (such as shunting, which redirects the flow of blood or fluid through other areas of the body) that help lower portal hypertension and prevent variceal bleeding may actually increase your risk for developing encephalopathy. Other factors that can contribute to encephalopathy include use of sedatives or narcotics, gastrointestinal bleeding, abnormal levels of electrolytes in the blood (especially low potassium levels), excess protein in the diet, infection such as peritonitis, dehydration, and constipation.

Without treatment, encephalopathy often becomes worse. Treatment may include reducing protein in the diet and taking lactulose, a type of sugar that the body cannot absorb, to help move stools through the intestines. Lactulose helps remove ammonia and other toxins that can cause encephalopathy. Lactitol, a food additive similar to lactulose, may be used in some countries to treat cirrhotic encephalopathy; it is not approved for use in the United States. Taking a supplement of the mineral zinc may help; talk to your doctor before adding a zinc supplement. You may also need antibiotics.