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Hepatopulmonary syndrome, the lung complication of liver disease that transplant can reverse.

Breathlessness in someone with cirrhosis is not always the liver, the ascites or the deconditioning. In up to a third of cases, the lungs themselves are the problem - and the fix is on the transplant list.

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Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against British Society of Gastroenterology, EASL and peer-reviewed hepatology and transplant sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK transplant practice, including MELD exception listing and contrast-enhanced echocardiography as the diagnostic standard.

Key facts

Hepatopulmonary syndrome at a glance.

The essentials, in plain English - what it is, who it affects, how it is diagnosed and what can be done about it.

  • What it is

    A triad of chronic liver disease, intrapulmonary vascular dilatation and arterial hypoxaemia - the lungs, not the heart, are the source of the breathlessness.

  • Who it affects

    Up to 20 to 30 per cent of people with cirrhosis - often unrecognised because breathlessness is blamed on ascites or deconditioning.

  • The mechanism

    Excess pulmonary nitric oxide causes vasodilation, ventilation-perfusion mismatch, a diffusion-perfusion defect and right-to-left shunting.

  • The clue on standing

    Platypnoea (worse standing, better lying) and orthodeoxia (oxygen falls on standing) - almost pathognomonic when they appear together.

  • The confirming test

    Contrast-enhanced (bubble) echocardiography - delayed left-atrial opacification after three heartbeats confirms an intrapulmonary shunt.

  • The definitive fix

    Liver transplantation - most cases reverse after transplant, and severe hypoxaemia qualifies for MELD exception points on the UK waiting list.

Why this guide matters

A lung problem that is really a liver problem.

Hepatopulmonary syndrome sits between two specialties, which is why it is so often missed. The three points below shape everything else on this page.

  • Suspect it in cirrhosis

    Anyone with chronic liver disease and unexplained breathlessness deserves an oxygen check and, if abnormal, a formal work-up.

  • Bubble echo is the key test

    Contrast-enhanced echocardiography is quick, safe and diagnostic - it is what separates hepatopulmonary syndrome from a purely cardiac shunt.

  • Transplant is the definitive fix

    Most cases reverse after liver transplantation, and severe disease qualifies for priority listing through MELD exception points.

How the diagnosis is made

From breathlessness to a firm answer.

The steps a UK hepatology or respiratory team will normally follow, in order - so you know what to expect and why.

  1. 01

    Assessing

    History in the context of liver disease

    Progressive breathlessness in someone with known cirrhosis or portal hypertension - the setting is what raises suspicion in the first place.

  2. 02

    Assessing

    Look for platypnoea and orthodeoxia

    Ask whether breathlessness eases when lying down, and measure oxygen saturation lying and standing - a fall of 5 per cent or more is highly suggestive.

  3. 03

    Assessing

    Examination - the peripheral signs

    Digital clubbing, spider naevi, cyanosis and the stigmata of chronic liver disease - all point towards the same diagnosis.

  4. 04

    Confirming

    Arterial blood gas

    Room-air PaO2 below 80 mmHg, or a widened alveolar-arterial gradient, defines the hypoxaemia that anchors the diagnosis.

  5. 05

    Confirming

    Contrast-enhanced echocardiography

    The gold-standard test - agitated saline microbubbles appearing in the left atrium after three or more beats confirms an intrapulmonary shunt.

  6. 06

    Confirming

    Technetium-99m MAA scan and CT chest

    MAA quantifies the shunt fraction; CT chest excludes emphysema, fibrosis or a pulmonary embolus that could otherwise explain the hypoxaemia.

  7. 07

    Preparing

    Specialist hepatology and transplant MDT

    Assessment is commissioned through a specialist liver unit - lung function with DLCO, MELD scoring and transplant listing are decided in an MDT setting.

Typical timeline: first specialist visit to firm diagnosis in weeks, once the right tests are booked.

Symptoms

What hepatopulmonary syndrome feels like.

The classic mix of breathlessness, posture-related oxygen changes and the peripheral signs of chronic liver disease - and the features that mean it is time to escalate.

  • Progressive breathlessness

    Dyspnoea on exertion in someone with cirrhosis - often creeping in over months and mistaken for deconditioning or ascites.

  • Platypnoea

    Breathlessness that is worse on standing and eases on lying flat - the single most characteristic symptom.

  • Orthodeoxia

    A measurable fall in oxygen saturation on moving from lying to standing - the objective counterpart of platypnoea.

  • Digital clubbing

    Nail-bed changes that develop as chronic hypoxaemia becomes established - a quiet but useful clue on examination.

  • Cyanosis

    Bluish discolouration of the lips, tongue or fingertips - reflects the underlying arterial hypoxaemia.

  • Spider naevi

    Central arteriolar lesions on the upper chest and face - a marker of the underlying liver disease driving the syndrome.

  • Signs of chronic liver disease

    Palmar erythema, jaundice, ascites and asterixis - the backdrop against which hepatopulmonary syndrome develops.

  • Red flag - severe hypoxaemia

    A resting PaO2 below 60 mmHg indicates severe disease, worsens prognosis and strengthens the case for expedited transplant assessment.

Treatment

How hepatopulmonary syndrome is managed in the UK.

Symptom control with oxygen and optimisation of the underlying liver disease - and, for those who qualify, liver transplantation as the only treatment that reliably reverses the syndrome.

  • Supplemental oxygen

    The mainstay of symptomatic care - improves exertional tolerance, protects vital organs and is often used long-term while awaiting transplant.

  • Treat the underlying liver disease

    Optimising cirrhosis care, alcohol abstinence, viral hepatitis treatment and portal-hypertension management do not reverse the syndrome but stabilise the wider picture.

  • Liver transplantation

    The only definitive treatment - most people see hypoxaemia reverse over months. Severe disease qualifies for MELD exception points and priority listing.

  • MELD exception listing

    UK transplant units can apply for exception points when PaO2 is severely reduced, moving eligible patients up the waiting list.

  • Pulmonary rehabilitation

    Structured exercise and breathing work can maintain function and quality of life during the wait for transplant.

  • Trial pharmacological options

    Methylene blue, garlic extract, inhaled nitric oxide and pentoxifylline have all been trialled - evidence remains limited and none is a standard treatment.

  • Selective coil embolisation

    Reserved for the uncommon patient with a single, large, discrete pulmonary arteriovenous shunt - a specialist-only intervention.

  • Palliative and supportive care

    For those who are not transplant candidates, symptom-focused care with oxygen, breathlessness management and psychological support is central.

What this guide is based on

The sources behind every claim on this page.

UK national guidance, European hepatology and respiratory statements and specialist transplant standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your hepatologist, respiratory physician or transplant team knows your case and can tell you which parts apply to you. If in doubt, ask them.

  • European Respiratory Society and European Association for the Study of the Liver. Statement on hepatopulmonary syndrome and portopulmonary hypertension.

  • British Society of Gastroenterology. Guidance on the management of cirrhosis and its pulmonary complications.

  • NHS Blood and Transplant. Liver transplantation - selection criteria and MELD exception points.

  • Peer-reviewed hepatology reviews on hepatopulmonary syndrome, pathophysiology and post-transplant outcomes.

Red flags

When hepatopulmonary syndrome needs urgent attention.

Most stable disease is followed in a hepatology clinic. These are the situations that need a faster route to a specialist or transplant centre.

  • Severe hypoxaemia

    A room-air PaO2 below 60 mmHg indicates severe hepatopulmonary syndrome and warrants urgent transplant-centre review.

  • New platypnoea in known cirrhosis

    Breathlessness that worsens on standing in someone with liver disease should prompt same-week specialist assessment.

  • Rapidly progressive breathlessness

    A sharp decline over weeks rather than months - consider superimposed portopulmonary hypertension or pulmonary embolus.

  • Cyanosis at rest

    Visible cyanosis without exertion suggests advanced disease and needs urgent oxygen assessment and referral.

  • Signs of decompensated liver disease

    Encephalopathy, tense ascites or variceal bleeding alongside breathlessness signals a decompensating picture and needs hospital care.

  • Fall in oxygen on modest exertion

    Desaturation on a short walk is common and helps quantify severity - it also strengthens the case for supplemental oxygen.

  • Suspected concurrent portopulmonary hypertension

    Right-heart signs on echocardiography change management and can preclude transplant if untreated - specialist assessment is essential.

  • Failure to improve after transplant

    Most cases reverse over 6 to 12 months. Persistent hypoxaemia beyond that window needs re-evaluation for alternative causes.

  • Access to a transplant centre

    Formal assessment can only be made at a designated UK liver-transplant unit - early referral matters.

Living with it

A hard diagnosis, with a real route back.

Four things that make the biggest difference day to day - honest oxygen use, pacing around posture, close contact with your team, and holding onto the fact that most people improve after transplant.

A quiet reminder

The waiting is part of the treatment.

Time on oxygen, time in rehab and time in transplant clinic are not delays - they are the treatment doing its work in the background.

  1. 01 Oxygen

    Use it, honestly

    If you have been prescribed supplemental oxygen, wear it during exertion, sleep and travel - it protects the brain, heart and kidneys while you wait for definitive treatment.

  2. 02 Rhythm

    Pace the day around posture

    Plan demanding tasks for times when you are rested and, where possible, seated - platypnoea makes standing the hardest position.

  3. 03 Team

    Stay close to your liver team

    Regular hepatology follow-up, transplant assessment updates and clear escalation routes are the backbone of good care.

  4. 04 Hope

    Transplant reverses most cases

    The evidence for reversal after transplant is strong - even severe hypoxaemia usually improves over the first year afterwards.

Frequently asked

Everything we get asked about hepatopulmonary syndrome.

Quick answers on platypnoea, bubble echocardiography, oxygen therapy and liver transplantation.

  • What is hepatopulmonary syndrome?

    Hepatopulmonary syndrome is a complication of chronic liver disease in which tiny blood vessels in the lungs dilate abnormally. This causes ventilation-perfusion mismatch and low blood oxygen, producing breathlessness in someone who has cirrhosis or portal hypertension. It affects up to 20 to 30 per cent of people with cirrhosis and is often underdiagnosed.

  • What is platypnoea and why does it matter?

    Platypnoea is breathlessness that is worse on standing and improves on lying flat, and orthodeoxia is a measurable fall in oxygen saturation on standing. Together they are almost characteristic of hepatopulmonary syndrome and should prompt a specialist review, ideally with contrast-enhanced echocardiography.

  • How is the diagnosis made?

    Diagnosis requires three things: chronic liver disease, arterial hypoxaemia on a blood gas (PaO2 below 80 mmHg or a widened alveolar-arterial gradient), and evidence of intrapulmonary vascular dilatation. The gold-standard test is contrast-enhanced (bubble) echocardiography, in which microbubbles reach the left atrium after three or more heartbeats.

  • Is there a medical treatment that reverses it?

    No, there is no proven medical treatment that reliably reverses hepatopulmonary syndrome. Methylene blue, garlic extract, inhaled nitric oxide and pentoxifylline have all been trialled with limited results. Supplemental oxygen relieves symptoms and protects vital organs, but liver transplantation is the only definitive treatment.

  • Can I get a liver transplant for hepatopulmonary syndrome?

    Yes. Liver transplantation is the definitive treatment, and most people see their oxygen levels normalise within 6 to 12 months. In the UK, patients with severe hypoxaemia can qualify for MELD exception points, which give them priority on the transplant waiting list. Assessment must be arranged through a specialist liver-transplant centre.

  • What is the prognosis without transplant?

    Untreated hepatopulmonary syndrome, particularly with severe hypoxaemia, is associated with a shorter life expectancy than cirrhosis alone. Supplemental oxygen and optimisation of the underlying liver disease help, but the trajectory of severe disease is best changed by transplantation. This is why early recognition and referral matter so much.

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