Medical Oncologist
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Hepatic encephalopathy: why the liver affects the brain | CION Cancer Clinics
When a scarred or cancer-filled liver can no longer clean toxins like ammonia from the blood, they reach the brain and slow it down. This is hepatic encephalopathy, and it is usually treatable and reversible. Families often mistake it for madness or stubbornness. This page explains the signs, the common triggers, how it is treated, and when new confusion means go to hospital today. At CION Cancer Clinics, our team supports patients and families through symptoms, follow-up and life during and after treatment.
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Medically reviewed by Dr. Naresh GunduConsultant Medical Oncologist · MBBS, DNB (Internal Medicine), DM (Medical Oncology, AIIMS) · last reviewed October 2026, next review due October 2027
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On this page
The short answer
Why does a sick liver make a person confused?
A healthy liver cleans toxins, mainly ammonia made in the gut, out of the blood. When cirrhosis or a large liver cancer stops it doing that job, those toxins reach the brain and slow it down. Doctors call this hepatic encephalopathy. It is usually treatable, and most episodes reverse once the trigger is found and treated.
Why families miss it
It rarely looks like a liver problem. Families describe a father who has become stubborn, a mother who is sleeping all day and awake all night, or a relative who seems to be going mad. Many take the person to a psychiatrist, a neurologist or a temple before anyone thinks of the liver. That delay matters, because each episode is easier to reverse when it is caught early.
Who this page is for
It is for families of someone with cirrhosis, primary liver cancer, or cancer that has spread widely through the liver. Confusion in a cancer patient can also come from the cancer reaching the brain, from medicines, from infection or from low salt in the blood. The doctor has to sort out which. For the wider list of causes, read confusion, drowsiness and odd behaviour.
This is a change in how the brain is working, not a change in who the person is. It is not madness, and it is not their fault.What sets it off
What usually triggers an episode?
An episode almost always has a trigger. Finding it is the first thing the doctor will do, because treating it is most of the treatment.
Constipation
The longer stool stays in the gut, the more ammonia is made and absorbed. It is one of the most common triggers, and one of the easiest to fix. See constipation as a trigger.
Infection
A urine infection, chest infection or infected fluid in the belly can tip a weak liver over. Fever is not always present.
Bleeding in the gut
Blood digested in the gut is a large protein load. Black stools with new confusion need hospital today.
Medicines and dehydration
Sleeping tablets, some painkillers, too many water tablets, vomiting or diarrhoea can all bring it on.
- Sleeping or anxiety tablets
- Strong painkillers
- Water tablets that dry the body out
- Alcohol, in any amount
Not sure whether this applies to you?
Ask an oncologist
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When to go to hospital today
Go to hospital today if someone with liver disease becomes newly confused, very drowsy, hard to wake, cannot recognise family, talks nonsense, or has a fit. Go the same day if confusion comes with fever, belly pain, vomiting blood or black stools. Do not give a sleeping tablet to calm them down. Do not wait to see whether they are better in the morning. Take the medicine list and recent reports with you. Read when confusion needs hospital admission.
How it is treated
What will the doctors do, and does it work?
Look for the trigger
Blood tests, a urine test, a check of the belly fluid and a look at the medicine list. Infection, bleeding and dehydration are treated first.
Clear the gut with lactulose
Lactulose is a sweet syrup that makes the bowels move and traps ammonia so it leaves in the stool. The doctor sets the amount so the person passes soft stools regularly. Read lactulose explained.
Add rifaximin if episodes keep coming back
Rifaximin is an antibiotic that stays in the gut and reduces the bacteria that make ammonia. It is usually added after a repeat episode.
Keep eating, including protein
The old advice to cut protein has changed. Muscle helps clear ammonia, and starving the patient makes things worse.
Recover and plan ahead
Most people clear over a few days. The hepatologist and oncologist then decide together what this means for cancer treatment.
What families notice
What does hepatic encephalopathy look like at home?
- Sleep turned upside down
- Sleepy all day, restless or awake at night. Often the first sign families notice.
- Personality change
- Irritable, stubborn, childish or unusually quiet. Families often read this as a mood problem.
- Forgetting and slowness
- Losing track of the day, slow answers, mistakes with money or phone numbers.
- Flapping hands
- When the arms are held out with the wrists bent back, the hands jerk or flap. Doctors call it asterixis.
- Changed handwriting
- Signatures and writing become shaky or smaller than before.
- Deep drowsiness
- Hard to wake, or not responding properly. This is the severe end and needs hospital today.
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Commonly believed
What do families often get wrong about it?
"He has gone mad. We need a mind doctor."
In someone with liver disease, new confusion is a liver problem until proven otherwise. Tell any doctor first that the person has cirrhosis or liver cancer.
"Once the brain is affected, it will never come back."
Most episodes reverse when the trigger is treated and the bowels are kept moving. People often return to how they were before.
"Stop all dal, eggs and meat. Protein is poison for the liver."
This is old advice. Liver patients usually need enough protein, spread through the day. Cutting it wastes muscle and can make confusion worse. Read should protein be reduced.
"Too many loose motions from the syrup is a side effect, so we stopped it."
Soft, regular stools are the point of lactulose. If it causes watery diarrhoea, call the doctor to adjust it rather than stopping it at home.
Being straight with you
What this page cannot tell you
It cannot tell you whether your relative's confusion is hepatic encephalopathy. Confusion in a person with cancer has many causes, including spread to the brain, low salt or sugar in the blood, infection, strokes and medicines. Only an examination and tests can separate them. Read is it encephalopathy or something else.
Who this does not apply to
Someone with a small liver tumour and a healthy liver is unlikely to develop encephalopathy. A person with dementia that came on slowly over years, with no liver disease, is in a different situation. Repeated or hard-to-control episodes also say something about how much liver reserve is left, which affects which cancer treatments are safe.
How CION fits in
CION oncologists take encephalopathy into account when planning cancer treatment, and the supportive care team helps families manage it at home. Hospital admission and hepatology care are coordinated through partner hospitals and hepatologists.
If the person is hard to wake, go to the nearest emergency department first. Call the cancer team after.Questions we are asked
Common questions about hepatic encephalopathy
Is hepatic encephalopathy reversible?
Usually, yes. Most episodes clear once the trigger is treated and lactulose keeps the bowels moving. Some people are left with mild slowness between episodes, and repeated episodes suggest the liver is weakening. The hepatologist will explain what to expect in your relative's case.
Is it the same as dementia?
No. Dementia usually comes on slowly over years and does not go away. Hepatic encephalopathy often appears over days, changes from day to day, and improves with treatment. An older person can have both, which is why doctors look carefully before deciding.
Does liver cancer itself cause it?
Mostly it comes from the cirrhosis that often sits behind liver cancer. A large tumour, or cancer that blocks blood flow through the liver, can also reduce how well the liver clears ammonia. Spread to the brain is a separate cause of confusion and is checked for separately.
Is an ammonia blood test enough to diagnose it?
Not on its own. The diagnosis is mainly made by examining the person and ruling out other causes. A normal ammonia level does not always rule it out, and a high one does not prove it. Doctors look at the whole picture.
Can it come back after one episode?
Yes, it often does. That is why lactulose is usually continued after the first episode, and rifaximin may be added after a second. Watching for constipation, infection and new tablets at home prevents many repeat episodes.
Can my relative still drive or handle money?
Even mild encephalopathy slows reaction time, so driving is not safe until a doctor says otherwise. Many families quietly take over banking and cooking with gas for a while. Read about safety at home.
Can cancer treatment continue after an episode?
Sometimes. It depends on how quickly the person recovers and how much liver function is left. Some treatments may be paused, changed or stopped. The oncologist and hepatologist make this decision together, and you should be part of that conversation.
Who should we call first?
If the person is very drowsy, hard to wake or has a fit, go to the nearest emergency department. For milder changes, or questions about lactulose and diet, call the CION helpline and a team member will guide you in Telugu or English.
Your Specialists
Meet CION's liver cancer specialists. Bring your scan reports and liver blood tests.
Our medical and surgical oncologists plan liver cancer care together, weighing the tumour and how well your liver works before choosing surgery, a liver-directed procedure or medicines.
Medical Oncologist
Dr. C. Raghavendra Reddy
MBBS(Gold Medal), DNB(General Medicine), DM(Medical Oncology)(Gold Medal)
Medical Oncologist
Dr. Bharati Devi Gorantla
MBBS, MD(General Medicine), DM(Medical Oncology)(Adyar,Chennai), ECMO, MRCP SCE(UK)
Medical Oncologist
Dr. Owais Mohammed
MBBS, MD (General Medicine), DrNB (Medical Oncology), ECMO, MRCP SCE (Medical Oncology) (UK)
Medical Oncologist
Medical Oncologist
Surgical Oncologist
Dr. Muralidhar Muddusetty
MBBS (AIIMS), MS (Surgery) (AIIMS), DNB (Surgical Oncology), MRCS (Edinburgh)
Surgical Oncologist
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Sources
- Liver UK (formerly British Liver Trust) — Hepatic encephalopathy (HE)
- Merck Manual Consumer Version — Hepatic Encephalopathy
- MedlinePlus — Loss of brain function - liver disease
- ESPEN — ESPEN practical guideline: clinical nutrition in liver disease
This page is general information, not a prescription. Do not change or stop any treatment based on what you read here. If anything is worrying you, contact your own treating team — or call our helpline and we will help you reach the right specialist.
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Is your relative more confused or sleepy than usual?
Tell us what has changed and what treatment they are on. A CION team member will help you work out the next step and who to see. One helpline serves every CION centre.