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Loss of brain function - liver disease


Loss of brain function occurs when the liver is unable to remove toxins from the blood. This is called hepatic encephalopathy. This problem may occur suddenly or develop slowly over time.

Alternative Names

Hepatic coma; Encephalopathy - hepatic; Hepatic encephalopathy


An important job of the liver is to make toxic substances in the body harmless. These substances may be made by the body, such as ammonia. Or they may be substances that you take in, such as medicines.

When the liver is damaged, these "poisons" can build up in the bloodstream and affect the function of the nervous system. The result may be hepatic encephalopathy.

This problem can occur suddenly and you may become ill very quickly. Causes include:

More often, the problem develops in people with chronic liver damage. Cirrhosis is the end result of chronic liver damage. Common causes of chronic liver disease in the United States are:

Once you have liver damage, episodes of worsening brain function may be triggered by:

Disorders that can appear similar to hepatic encephalopathy include:

In some cases, hepatic encephalopathy is a short-term problem that can be corrected. It may also occur as part of a chronic problem from liver disease that gets worse over time.


Symptoms may begin slowly and slowly get worse. They may also begin suddenly and be severe from the start.

Early symptoms may be mild and include:

More severe symptoms may include:

People with hepatic encephalopathy can become unconscious, unresponsive, and possibly enter a coma.

People are often not able to care for themselves because of these symptoms.

Exams and Tests

Signs of nervous system changes may include:

Tests may include:


If changes in brain function are severe, a hospital stay may be needed.

Medicines are given to help lower ammonia levels and improve brain function. You may need to take these medicines every day.

If the problem is very bad, you may need to cut down the protein in your diet. Talk to a dietitian about how to change your diet and avoid poor nutrition. People who are very ill may need intravenous or tube feedings.

Certain medicines should be avoided

Your health care provider may suggest other medicines and treatments. These may have varying results.

Outlook (Prognosis)

Acute hepatic encephalopathy may be treatable. Chronic forms of the disorder often continue to get worse and come back.

Both forms of the condition may result in irreversible coma and death. The majority of people who go into a coma will die. The chances of getting better vary from person to person.

When to Contact a Medical Professional

Call your health care provider if you or people around you notice any problems with your mental state or nervous system function. This is very important for people who already have a liver disorder. Hepatic encephalopathy can get worse quickly and become an emergency condition.


Treating liver problems may prevent hepatic encephalopathy. Avoiding heavy drinking and intravenous drug use can prevent many liver disorders.


Garcia-Tsao G. Cirrhosis and its sequelae. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 153.

Leise MD, Poterucha JJ, Kamath PS, Kim WR. Management of hepatic encephalopathy in the hospital. Mayo Clin Proc. 2014;89(2):241-53. PMID 24411831

Nevah MI, Fallon MB. Hepatic encephalopathy, hepatorenal syndrome, hepatopumonary syndrome, and systemic complications of liver disease. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 10th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 94.

Review Date: 8/14/2015
Reviewed By: Subodh K. Lal, MD, gastroenterologist at Gastrointestinal Specialists of Georgia, Austell, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.