Hepatic Encephalopathy: Symptoms, Causes, and Treatment Explained
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026
Hepatic encephalopathy is a serious brain-function condition caused when a damaged liver cannot filter toxins — especially ammonia — from the blood. It affects 30% to 40% of people with cirrhosis and can progress to coma or death without prompt treatment. Common warning signs include confusion, personality changes, a flapping tremor, and daytime sleepiness. Early stages are often hard to notice, but the condition is treatable if caught early, with medicines like lactulose and rifaximin, plus lifestyle changes. Sudden confusion or unresponsiveness in someone with liver disease is a medical emergency — call 911.
Quick Answer
What it is: a condition in which a failing liver allows toxins such as ammonia to build up in the blood and disrupt brain function.
How common: it occurs in 30% to 40% of people who have cirrhosis.
Key warning signs: confusion, trouble focusing, memory loss, personality changes, flapping tremor, slurred speech, and daytime sleepiness.
Emergency rule: call 911 or go to the emergency room if someone with liver disease has sudden confusion, cannot wake up, or acts unusually.
How it's measured: five severity grades (0–4) based on the West Haven criteria; grades 0–1 are "covert" (hidden), grades 2–4 are "overt" (noticeable).
Treatment: find and treat the trigger (infection, bleeding, constipation), lower ammonia with medicines such as lactulose and rifaximin, and in advanced cases consider enema, TIPS, or liver transplant.
Outlook: it is treatable when caught early, but even successful treatment usually leaves underlying liver disease requiring ongoing care.
What Is Hepatic Encephalopathy?
Hepatic encephalopathy (huh-PAT-ik en-sef-uh-LOP-uh-thee) is a serious condition that develops when the liver is unable to filter toxins from the blood, including ammonia from the intestines. That buildup of toxins interferes with the brain's ability to function.
The condition can be caused by injury to the liver, liver cancer, or a chronic liver disease that results in liver failure, such as cirrhosis — advanced scarring of the liver. Alcohol use, infections, the use of some medicines, and blood clots in the veins also may cause it.
Why it matters: If left untreated or not treated successfully, hepatic encephalopathy can lead to unresponsiveness, coma, or death. Prompt treatment is needed. If you think you or a loved one might have it, call 911 or emergency medical help.
Hepatic encephalopathy occurs when a damaged liver cannot clear toxins such as ammonia from the blood, allowing them to reach the brain and disrupt its function.
Is Hepatic Encephalopathy Curable?
Though hepatic encephalopathy may lead to death, it is treatable if caught early. Finding and treating the underlying cause is a key part of care, and it usually requires daily treatment to prevent further decline. However, even when treatment succeeds, in most cases the person still has advanced liver disease that needs ongoing management.
The 3 Types of Hepatic Encephalopathy
Doctors classify hepatic encephalopathy into three types based on what caused the liver problem:
Type A (acute liver failure): liver function is lost quickly, in days or weeks
Type B (portosystemic shunt): blood bypasses the liver through an abnormal opening between the portal vein and the hepatic vein (the vein that carries blood from the liver to the heart)
Type C (cirrhosis): advanced scarring of the liver; also occurs with acute-on-chronic liver failure, a rapid decline in people with chronic liver failure
The condition can also be described by how it behaves. Acute hepatic encephalopathy comes on suddenly, while chronic hepatic encephalopathy is long-lasting.
8 Hepatic Encephalopathy Symptoms and Warning Signs
Common symptoms of hepatic encephalopathy affect thinking, behavior, and movement:
Trouble focusing or paying attention: difficulty concentrating on conversations or tasks
Disorientation: not knowing where you are
Sleep problems: sleepiness during the day or trouble sleeping at night
Memory loss or confusion: forgetting things, feeling muddled
Flapping tremor in the limbs: a characteristic trembling, especially in the arms and hands
Personality or mood changes: acting out of character
Slurred speech or movement: difficulty speaking clearly or moving normally
Coma: falling into unresponsiveness
Over time, these symptoms can lower quality of life and the ability to function day to day. Having other chronic conditions alongside hepatic encephalopathy may make daily life even harder.
When to See a Doctor (and When It's an Emergency)
The early stages of hepatic encephalopathy may be hard to notice. In the earliest grades, family members often help the healthcare team by describing behavior changes.
Emergency rule: If you or someone with liver disease has sudden confusion, cannot wake up, or displays unusual behavior, call your healthcare professional or go to a hospital emergency room right away.
Eight common warning signs of hepatic encephalopathy, the factors that raise risk, and the three signs that require care right away.
What Causes Hepatic Encephalopathy?
The root cause is a buildup of toxins — especially ammonia — when the liver cannot filter waste from the blood. Several specific events can set off that buildup:
Alcohol use and cirrhosis: damages the liver's filtering ability
Electrolyte imbalances: low potassium or low sodium levels disturb body chemistry
Infections: add stress and toxins the failing liver cannot clear
Digestive-tract bleeding: blood in the gut increases ammonia production
Liver transplant complications: can temporarily upset liver function
Liver shunt surgery: placing shunts to improve blood flow can let toxins bypass the liver
Other factors that may cause an episode include certain medicines (diuretics, opioids, and sedatives), dehydration from vomiting or diarrhea, constipation, and older age.
13 Risk Factors for Hepatic Encephalopathy
You are more likely to develop hepatic encephalopathy if you have any of the following:
Advanced liver disease such as cirrhosis
Kidney disease
Diabetes
Epilepsy
Low muscle mass (sarcopenia)
Large portosystemic shunts in the liver
Low sodium or high ammonia in the blood
Certain genetic risk factors
Older adult age
Alcohol use
Poor eating habits
Diuretics, proton-pump inhibitors, opioids, or benzodiazepine medicines
History of hepatic encephalopathy
8 Possible Complications
Untreated or poorly controlled hepatic encephalopathy can lead to serious complications, including lasting memory and attention problems, falls and injuries, trouble driving, sleep disturbances, repeated hospitalizations, coma, and death.
Prevention: 8 Ways to Reduce Your Risk
If you have liver disease, you can lower your chances of developing hepatic encephalopathy by taking care of your health:
Take prescription medicines as prescribed: keeps liver disease under control
Eat protein from plants and dairy: supports nutrition without overtaxing the liver
Avoid alcohol and sedating medicines: removes major triggers
Avoid opioids: reduces sedation and constipation risk
Stay hydrated: prevents dehydration-triggered episodes
Prevent constipation: keeps ammonia moving out of the body
Treat infections as soon as they appear: stops a common trigger early
Get regular checkups for liver disease: catches problems before episodes begin
How Is Hepatic Encephalopathy Diagnosed?
Hepatic encephalopathy is diagnosed by looking at the medical history, signs and symptoms, medicine use, and the results of blood and other tests:
Psychological exam: thinking skills when symptoms are hard to detect, such as in covert cases; one test involves naming animals
Neuropsychological tests: pencil-and-paper tasks that assess thinking, motor skills, speed, and hand coordination (e.g., the Psychometric Hepatic Encephalopathy Score, and reaction-time tests)
Blood tests: ammonia, electrolytes, glucose, and C-reactive protein; rule out similar conditions like diabetes and stroke; check whether infections, alcohol, or medicines are a factor
Electroencephalogram (EEG): electrical activity in the brain, which helps gauge severity
Imaging tests (CT scan or MRI): views of the liver and blood vessels to rule out stroke, seizures, or other causes; gut-area scans may show blood-flow issues
The 5 Stages of Hepatic Encephalopathy (West Haven Criteria)
Doctors grade the severity of hepatic encephalopathy using the West Haven criteria. Family members can be especially helpful at this step, since early behavior changes are easier for loved ones to spot than for the patient:
Grade 0 (covert/hidden): no symptoms; the condition is found only by tests
Grade 1 (covert/hidden): sleep issues, mild confusion, mood swings
Grade 2 (overt/noticeable): disorientation, unusual behavior, possible daytime drowsiness
Grade 3 (overt/noticeable): extreme confusion and sleepiness, but still responds to others
Grade 4 (overt/noticeable): hepatic coma; the person cannot respond to others
Grades 0 and 1 are called covert hepatic encephalopathy because the condition may not be noticeable. Grades 2 through 4 are called overt because the symptoms are noticeable. In advanced stages, doctors may use the Glasgow Coma Scale to assess verbal and physical responses to sound, touch, and other stimuli in people who are not conscious.
How Is Hepatic Encephalopathy Treated?
Treatment usually requires locating the source of infection or bleeding and treating it. If the episode is severe, treatment in the intensive care unit (ICU) may be needed, where the care team closely monitors the patient and treats complications such as pneumonia.
The pathway from exam and blood tests to staging, trigger treatment, ammonia-lowering medicines, and advanced options such as TIPS or liver transplant. Daily care habits support recovery at every stage.
Medicines That Lower Ammonia
Lactulose: lowers ammonia by increasing bowel movements and may improve gut health; given by mouth or enema
Rifaximin (Xifaxan): an antibiotic that kills bacteria in the gut; may reduce the risk of future overt episodes
L-ornithine L-aspartate (LOLA): a compound given to reduce ammonia levels in the body
PEG laxatives (polyethylene glycol): empty the bowel quickly
Zinc supplement: may help convert ammonia into compounds the body can pass out
Surgery and Other Procedures
Depending on the grade and severity, the healthcare team may recommend additional procedures:
Bowel enema: if constipated or dehydrated, to restore hydration
TIPS surgery (transjugular intrahepatic portosystemic shunt): may improve blood flow, but can worsen hepatic encephalopathy in some people; medicine is taken after surgery to lower recurrence risk
Liver transplant: replaces the liver with a healthy organ from a deceased donor or part of a liver from a living donor; may reverse hepatic encephalopathy; often the best option after overt episodes and the only option for end-stage liver disease
Timing for a transplant varies, and the care team will order tests to see if transplantation is an option. Depending on where you live, hepatic encephalopathy may not be a condition that allows placement on a transplant waiting list.
Lifestyle and Dietary Changes That Help
Daily habits form a key part of long-term management:
Medication changes: adjusting medicines for other conditions to reduce fall risk
Vitamins: a multivitamin if nutrient levels are low
Dietary changes: a healthy diet to manage the condition and its causes, such as cirrhosis — ask the team before changing your diet
Meal timing: small meals during the day may improve mental performance and make lactulose easier to take
Regular exercise: start with short, easy sessions and build strength, balance, and endurance over time
Home modifications: a safe living space reduces falls and injuries
Honest outlook: Hepatic encephalopathy is a complex condition. Treating it at a less severe grade may not reduce the risk of a more severe case later. Even if treatment succeeds, in most cases advanced liver disease remains.
Bottom Line
Hepatic encephalopathy is a serious but treatable complication of liver disease. It strikes when a damaged liver can no longer clear toxins like ammonia, allowing them to disrupt brain function — and it affects 30% to 40% of people with cirrhosis. Because the earliest stages are often hidden, caregivers and family members play a crucial role in spotting the warning signs: confusion, personality changes, a flapping tremor, and sleep disturbances.
With early recognition and daily treatment — ammonia-lowering medicines, trigger management, and lifestyle changes — many people can avoid further decline and preserve quality of life. The condition does, however, require constant vigilance.
Your next step: If you or a loved one has liver disease, ask your healthcare team about your personal risk for hepatic encephalopathy, which symptoms should trigger an immediate call, and how to create a safety plan at home. And remember — sudden confusion or unresponsiveness in someone with liver disease is a medical emergency. Call 911 without delay.
Explore more of our liver health guide: fatty liver disease (MASLD) and how it's tested and treated.
Frequently Asked Questions
What is hepatic encephalopathy in simple terms?
Hepatic encephalopathy is a brain-function condition that happens when a damaged liver cannot filter toxins — especially ammonia — from the blood. The toxin buildup affects how the brain works, causing confusion, behavior changes, and in severe cases, coma.
Is hepatic encephalopathy an emergency?
It can be. If someone with liver disease develops sudden confusion, cannot wake up, or behaves unusually, call 911 or go to the emergency room right away. Prompt treatment is needed to prevent coma or death.
What are the first signs of hepatic encephalopathy?
Early signs are easy to miss: trouble focusing, daytime sleepiness, mood or personality changes, and mild confusion. Family members are often the first to notice these changes. As it progresses, a flapping tremor, disorientation, and slurred speech may appear.
What is the difference between covert and overt hepatic encephalopathy?
Covert hepatic encephalopathy covers grades 0–1, when there are few or no noticeable symptoms and the condition is found only by tests. Overt hepatic encephalopathy covers grades 2–4, when confusion, unusual behavior, and eventually coma become clearly noticeable.
How is the severity of hepatic encephalopathy measured?
Doctors use the West Haven criteria, which assign one of five grades (0 through 4) based on symptoms. Grade 0 has no symptoms, and grade 4 is hepatic coma with no response to others.
Can hepatic encephalopathy be cured?
It is treatable — especially when caught early — but usually not curable on its own. Medicines like lactulose and rifaximin lower ammonia levels, and a liver transplant may reverse the condition. However, even with successful treatment, most people still have advanced liver disease that needs ongoing care.
What medicines treat hepatic encephalopathy?
The main medicines are lactulose (which increases bowel movements to remove ammonia), rifaximin (an antibiotic that reduces gut bacteria that produce ammonia), polyethylene glycol laxatives, L-ornithine L-aspartate (LOLA), and sometimes zinc supplements.
Can you live a normal life with hepatic encephalopathy?
Many people manage the condition well with daily medicines, a healthy diet, small frequent meals, hydration, regular exercise, and fall-prevention steps at home. Because it can recur and progress, staying closely connected to a care team is essential.
References
This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. This guide is based on peer-reviewed medical sources last updated on May 31, 2025.
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