Pulmonary Hypertension

Introduction

Pulmonary hypertension, often shortened to PH, is a condition in which the blood pressure inside the arteries of the lungs is higher than it should be. Over time, this raised pressure puts strain on the right side of the heart, which has to work harder to push blood through the lungs. If you or someone in your family has been told they have pulmonary hypertension, you are likely now thinking about what the diagnosis means, what treatments are available, and what daily life will look like from here.

This article walks through what pulmonary hypertension is, the different types and their causes, how doctors diagnose and stage the condition, the medications and procedures used to treat it, and how people manage life with PH over the long term. It is written for patients and families who are past the early days of figuring out what is wrong, and who now need a clear, calm guide to the road ahead.

Pulmonary hypertension is a serious condition, but the treatment landscape has changed substantially over the past two decades. Several classes of medication that did not exist a generation ago are now standard care, and outcomes for many people are better than they once were. Care is best delivered by a specialist team experienced in PH, because both diagnosis and treatment can be complex.

What Is Pulmonary Hypertension?

To understand pulmonary hypertension, it helps to know how blood normally moves through the lungs. The right side of the heart pumps blood into the pulmonary arteries, which carry it through the lungs to pick up oxygen. The blood then returns to the left side of the heart and is pumped out to the rest of the body.

The right heart pumps blood through the pulmonary arteries to the lungs and back.

AI-generated illustration

In a healthy adult, the pressure in the pulmonary arteries is much lower than the pressure in the rest of the body's arteries. In pulmonary hypertension, that pressure is abnormally high. The most recent European Society of Cardiology and European Respiratory Society (ESC/ERS) guidelines define pulmonary hypertension as a mean pulmonary artery pressure greater than 20 mmHg, measured during a procedure called a right heart catheterisation.

Higher pressure in the pulmonary arteries has two main consequences:

• The right ventricle — the chamber of the heart that pumps into the lungs — has to work harder against the resistance. Over time, this can lead to right heart failure.
• The exchange of oxygen in the lungs can become less efficient, leading to breathlessness, fatigue, and reduced exercise tolerance.

Pulmonary hypertension is not a single disease. It is a state that can arise from many different underlying problems, ranging from disorders of the pulmonary arteries themselves to left-sided heart disease, chronic lung disease, blood clots, and other causes. The treatment depends heavily on which type of PH a person has.

Types of Pulmonary Hypertension

The World Health Organization classification, which is also used by ESC/ERS and major cardiology and pulmonology societies, sorts pulmonary hypertension into five groups. Each group has a different mechanism and a different treatment approach, which is why the classification matters for care planning.

Group 1: Pulmonary Arterial Hypertension (PAH)

In pulmonary arterial hypertension, the small arteries inside the lungs become narrowed, thickened, and stiff. This is a disease of the pulmonary arteries themselves. Group 1 includes:

Cross-sections comparing a healthy pulmonary artery with an artery narrowed by pulmonary arterial hypertension.

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• Idiopathic PAH — where no underlying cause is found.
• Heritable PAH — linked to specific gene changes that can run in families.
• Drug- and toxin-induced PAH — associated with certain appetite suppressants, some chemotherapy agents, and other substances.
• PAH associated with other conditions — such as connective tissue diseases (scleroderma is a common one), HIV infection, portal hypertension from liver disease, and congenital heart defects.

Group 1 PAH is the type that is treated with the specific pulmonary vasodilator medications discussed later in this article.

Group 2: PH Due to Left Heart Disease

This is the most common form of pulmonary hypertension worldwide. When the left side of the heart does not pump or relax normally — for example, in heart failure or significant mitral or aortic valve disease — blood backs up into the lungs, raising pressure in the pulmonary arteries.

The key point about Group 2 is that the underlying left-heart problem is what needs to be treated. PAH-specific medications are generally not appropriate here and can sometimes cause harm.

Group 3: PH Due to Lung Disease or Hypoxia

Long-term lung diseases — including chronic obstructive pulmonary disease (COPD), interstitial lung disease, sleep-disordered breathing, and living at very high altitude — can raise pressure in the pulmonary arteries. The lungs respond to low oxygen by tightening the pulmonary arteries, and over time this can become permanent.

Treatment in Group 3 focuses on the underlying lung disease, oxygen therapy where indicated, and management of sleep apnoea if present.

Group 4: Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

CTEPH develops when blood clots in the lungs (pulmonary emboli) do not fully dissolve and instead become scar-like tissue that blocks or narrows the pulmonary arteries. CTEPH is important to identify because, in many cases, it can be surgically treated and potentially cured. Every person with suspected PH is screened for CTEPH, usually with a ventilation-perfusion (V/Q) scan.

Group 5: PH with Unclear or Multifactorial Mechanisms

This group includes pulmonary hypertension caused by, or associated with, conditions like sarcoidosis, certain blood disorders (such as sickle cell disease), chronic kidney disease on dialysis, and metabolic disorders. The mechanisms can be mixed, and treatment is directed at the underlying condition.

Causes and Risk Factors

The cause of pulmonary hypertension depends on which group it falls into. Some causes are clear from a person's medical history; others require investigation.

Common contributors and risk factors include:

• Left-sided heart disease — the leading global cause of PH.
• Chronic lung disease — especially COPD and interstitial lung disease.
• Previous blood clots in the lungs — raising the possibility of CTEPH.
• Connective tissue diseases — particularly systemic sclerosis (scleroderma), lupus, and mixed connective tissue disease.
• Congenital heart defects — especially those with long-standing left-to-right shunts.
• HIV infection.
• Liver disease with portal hypertension.
• Certain medications and toxins — including some weight-loss drugs and methamphetamine use.
• Family history — some forms of PAH are heritable. The most commonly identified gene is BMPR2.
• Sleep apnoea, particularly when severe and untreated.
• Sickle cell disease and other haemolytic disorders.
• Schistosomiasis — an important cause in regions where this parasitic infection is common.

Idiopathic PAH, where no cause is identified despite full investigation, is more commonly diagnosed in younger and middle-aged women, although it can occur at any age and in any sex.

Signs and Symptoms

If you are reading this after a diagnosis, you will already be familiar with how pulmonary hypertension feels. The reason this section still matters is that symptoms can worsen over time, and recognising change early helps your specialist adjust treatment.

Common symptoms include:

• Breathlessness, particularly on exertion — often the first and most prominent symptom.
• Fatigue and reduced ability to do activities you previously managed easily.
• Chest pain or pressure on exertion.
• Light-headedness or fainting, especially during or just after physical effort. This is a warning sign that should be reported promptly.
• Palpitations — an awareness of the heart racing or beating irregularly.
• Swelling of the ankles, legs, or abdomen as the right side of the heart begins to struggle.
• A bluish tinge to the lips or fingertips (cyanosis) in more advanced disease.

Doctors use a system called the WHO functional class to describe how much PH is affecting daily life. It ranges from Class I (no limitation of activity) to Class IV (symptoms at rest, unable to do physical activity without symptoms). Knowing your functional class helps both you and your specialist track how the condition is changing.

New or worsening symptoms — such as fainting, chest pain, worsening swelling, or rapid weight gain — should be reported to your specialist team without delay.

Diagnosis

Diagnosing pulmonary hypertension involves more than confirming raised pressure in the lungs. It also involves working out which of the five groups a person belongs to, because the treatment differs so much between them. A thorough workup typically includes the following.

Echocardiogram

An echocardiogram is an ultrasound of the heart. It is usually the first test that suggests pulmonary hypertension, by estimating the pressure in the pulmonary arteries and showing how the right side of the heart is coping. It is non-invasive and widely available, but it gives an estimate, not a definitive measurement.

Right Heart Catheterisation

Right heart catheterisation is the test that confirms the diagnosis. A thin tube is passed through a vein, usually in the neck or groin, into the right side of the heart and the pulmonary artery. Pressure is measured directly. This test also helps distinguish PAH (Group 1) from PH due to left heart disease (Group 2) and provides information used to guide treatment.

A catheter is guided from a neck or groin vein through the right heart into the pulmonary artery to measure pressure directly.

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For many people, a vasoreactivity test is done during the same procedure. A short-acting medication that relaxes the pulmonary arteries is given, and the response is measured. A positive response identifies a small group of patients who may benefit from a specific class of medication called calcium channel blockers.

Imaging

• Chest X-ray — can show an enlarged heart or pulmonary arteries.
• CT scan of the chest, sometimes with contrast (CT pulmonary angiogram) — looks at the lungs and blood vessels.
• Ventilation-perfusion (V/Q) scan — the test used to screen for CTEPH (Group 4). This is important because CTEPH can be missed on a CT scan.
• MRI of the heart — sometimes used to assess right ventricular function in detail.

Blood Tests

Blood tests look for underlying causes such as connective tissue disease, HIV, liver disease, and thyroid problems. A blood test called NT-proBNP or BNP measures a marker of heart strain and is often used to monitor PH over time.

Lung Function Tests and Sleep Studies

Pulmonary function tests assess for underlying lung disease (Group 3). A sleep study may be done if sleep apnoea is suspected.

Six-Minute Walk Test

This simple test measures how far you can walk in six minutes. It is used both at diagnosis and during follow-up to track exercise capacity over time.

Genetic Testing

For people with idiopathic PAH or a family history of PAH, genetic counselling and testing may be offered. The most commonly identified gene change is in BMPR2, but several others are known.

Treatment and Management

Treatment of pulmonary hypertension has two layers: treating the underlying cause where possible, and treating the raised pressure and its consequences. The right combination depends on which group of PH a person has.

Treating the Underlying Cause

For Groups 2, 3, 4, and 5, treating the underlying problem is the priority:

• Group 2 (left heart disease) — optimising heart failure medications, treating valve disease, controlling blood pressure and atrial fibrillation if present.
• Group 3 (lung disease) — treating COPD, interstitial lung disease, or sleep apnoea; long-term oxygen therapy where appropriate.
• Group 4 (CTEPH) — specific surgical and medical options, described below.
• Group 5 — treating the associated condition (for example, sickle cell disease, sarcoidosis).

PAH-Specific Medications (Mainly Group 1)

For pulmonary arterial hypertension (Group 1), several classes of medication have been developed that target the abnormal narrowing of the pulmonary arteries. These are sometimes called pulmonary vasodilators. They are also used for inoperable or persistent CTEPH (Group 4), and one drug is specifically approved for that purpose.

The main classes are:

• Endothelin receptor antagonists (ERAs) — for example, bosentan, ambrisentan, and macitentan. They block a substance in the body that narrows blood vessels.
• Phosphodiesterase-5 inhibitors (PDE-5i) — for example, sildenafil and tadalafil. They help relax the pulmonary arteries through the nitric oxide pathway.
• Soluble guanylate cyclase (sGC) stimulators — riociguat. This medication is used in PAH and is also specifically used for inoperable or persistent CTEPH.
• Prostacyclin pathway agents — epoprostenol, treprostinil, iloprost, and selexipag. These are powerful pulmonary vasodilators given by intravenous infusion, subcutaneous infusion, inhalation, or by mouth, depending on the specific drug.
• Calcium channel blockers — used only for the small subset of patients who show a positive vasoreactivity test during right heart catheterisation.

Current ESC/ERS guidelines recommend that most people newly diagnosed with PAH start on a combination of two of these medications rather than one alone, with prostacyclin pathway agents added when the disease is more severe or not responding adequately. Treatment is typically guided by risk assessment: doctors use a set of measures (functional class, walk distance, blood markers, heart imaging) to classify risk as low, intermediate, or high, and step treatment up if a person is not in a low-risk category.

Supportive Medications

Beyond the PAH-specific drugs, several supportive medications are commonly used:

• Diuretics (water tablets) — to reduce fluid retention and swelling.
• Oxygen therapy — for people whose blood oxygen levels are low.
• Anticoagulants (blood thinners) — standard treatment for CTEPH; their use in idiopathic PAH is more selective and individualised.
• Iron supplementation — iron deficiency is common in PH and treating it can help symptoms.

Procedures and Surgery

For some forms of pulmonary hypertension, procedures or surgery are part of treatment:

• Pulmonary endarterectomy — the operation for CTEPH (Group 4). It involves removing the organised clot material from the pulmonary arteries. In specialist centres, this surgery can dramatically improve or cure CTEPH for suitable candidates.
• Balloon pulmonary angioplasty (BPA) — a catheter-based procedure used for people with CTEPH who are not suitable for surgery, or who have residual disease after surgery.
• Atrial septostomy — a procedure that creates a small opening between the upper chambers of the heart, used as a bridge to transplant or as palliation in severe disease, in selected cases.
• Lung transplant or heart-lung transplant — considered for people with advanced PAH whose disease is not responding adequately to medical therapy. Referral for transplant evaluation is often made earlier than people expect, because the assessment itself takes time.

Lifestyle and Self-Management

Day-to-day choices have a real effect on how well people live with pulmonary hypertension. Most PH specialist teams discuss the following with patients.

Physical Activity

People with PH were once told to avoid almost all exercise. Current guidance is different. Supervised exercise rehabilitation, designed for PH, can improve exercise capacity and quality of life. The key is that it should be tailored and ideally supervised, especially at the start. Very heavy lifting, isometric exercises, and activities that cause sudden severe breathlessness or dizziness are usually discouraged.

Pregnancy

Pregnancy carries a significantly increased risk in pulmonary arterial hypertension and is generally advised against. Several PAH medications are also unsafe in pregnancy. Reliable contraception is an important conversation, and women of reproductive age with PAH are encouraged to discuss family planning openly with their specialist team.

Vaccinations

Vaccinations against influenza, pneumococcal infection, and COVID-19 are recommended for people with PH, because chest infections can cause significant deterioration.

Altitude and Air Travel

High altitude reduces the oxygen in the air and can worsen pulmonary hypertension. Travel to high-altitude destinations may not be advisable, and air travel may require supplemental oxygen for some people. This is best discussed with your specialist before any trip.

Diet, Fluid, and Salt

Many people with PH are advised to limit salt and to keep an eye on fluid intake, particularly if there is fluid retention. Daily weights help spot fluid build-up early.

Smoking and Alcohol

Stopping smoking is important for everyone with PH. Alcohol is usually moderated, particularly where it can interact with medications or worsen liver disease.

Mental Health

Living with PH can be emotionally difficult. Anxiety and depression are common and treatable. Mentioning low mood, anxiety, or sleep problems to your specialist team is as important as reporting physical symptoms.

Monitoring and Targets

Pulmonary hypertension is monitored regularly, usually every three to six months in stable patients, more often when treatment is being changed. Monitoring is built around the idea of risk assessment: doctors look at a set of measures together and decide whether you are in a low-, intermediate-, or high-risk category, and whether treatment should be adjusted to move you toward low risk.

Risk stratification in pulmonary hypertension guides treatment decisions using several measures assessed together.

AI-generated illustration

Measures typically tracked include:

• WHO functional class.
• Six-minute walk distance.
• NT-proBNP or BNP blood levels.
• Echocardiographic measures of right heart size and function.
• Sometimes a repeat right heart catheterisation, especially if treatment is being escalated or transplant is being considered.

The goal of treatment, where possible, is to reach and maintain a low-risk profile, with good exercise capacity, stable right heart function, and a quality of life that allows the activities that matter to you.

Complications

The complications of pulmonary hypertension are mainly related to right heart strain and reduced oxygen delivery. They include:

• Right heart failure — the most important long-term complication. Symptoms include increasing swelling, breathlessness, abdominal bloating, and fatigue.
• Arrhythmias — abnormal heart rhythms, particularly atrial flutter and atrial fibrillation, which can cause sudden worsening.
• Blood clots — the risk of clots in the lungs is raised in some forms of PH.
• Bleeding from the lungs (haemoptysis) — uncommon but can occur, especially in advanced disease.
• Anaemia and iron deficiency — common and worth treating.
• Liver congestion — from the right heart backing up.

Most of these complications are reasons to stay in regular contact with the specialist team and to report new or worsening symptoms early.

Living with Pulmonary Hypertension

For most people, living well with pulmonary hypertension means working with a specialist PH centre over the long term, taking medications consistently, attending follow-ups, and learning to read your own body. Several practical points come up again and again in PH clinics.

Working With a Specialist Centre

PH is uncommon and the medications and procedures used to treat it are specialised. Care at a centre with experience in PH with cardiology, pulmonology, imaging, and sometimes rheumatology and surgery working together is widely recommended by major societies. Your local doctor remains important for general care, but PH-specific decisions are usually made by, or in close contact with, the specialist team.

Taking Medications Consistently

Several PAH medications must be taken exactly as prescribed, at the same times each day. Some, like continuous infusions of prostacyclin, require careful daily handling and a back-up plan if equipment fails. Patient education and support from the PH team are part of safe long-term use.

Recognising Worsening

Learning to spot warning signs is one of the most useful things you can do. New or worsening:

• Breathlessness at rest or with much less exertion than before.
• Swelling in the legs or abdomen.
• Weight gain over a few days.
• Fainting or near-fainting.
• Chest pain.
• Palpitations.

…are all reasons to contact the specialist team rather than waiting for the next routine appointment.

Work, Relationships, and Daily Life

Many people with PH continue to work, travel within reason, and maintain active relationships. Pacing learning what causes symptoms and planning activities around energy levels becomes an important everyday skill. PH support groups, in person or online, are useful for many people in normalising the day-to-day experience.

Outlook

The outlook in pulmonary hypertension depends heavily on the type, severity at diagnosis, response to treatment, and how the right side of the heart is coping. PAH was historically associated with a poor outlook, but the introduction of targeted medications over the past two decades has substantially improved survival and quality of life for many people. CTEPH can be cured in some cases with surgery. Group 2 and Group 3 PH outlooks depend mainly on the underlying heart or lung condition. Your specialist is the best person to give you an individualised picture, because the relevant numbers depend on so many specific factors.

Pulmonary Hypertension in Children

Pulmonary hypertension also occurs in children, including newborns. Although there are similarities to adult PH, the causes, classification, and treatment have important differences, and care is delivered by paediatric PH specialists.

Causes in Children

The most common causes in children include:

• Congenital heart disease — particularly defects that allow extra blood flow to the lungs.
• Persistent pulmonary hypertension of the newborn (PPHN) — a condition affecting some newborns where the normal drop in lung pressure after birth does not happen.
• Lung disease of prematurity, including bronchopulmonary dysplasia.
• Idiopathic and heritable PAH.
• Developmental lung disorders.

Diagnosis and Treatment

Echocardiography is central in children, and right heart catheterisation is done in specialised paediatric cardiac units. Several of the PAH medications used in adults are used in children, often with weight-based dosing. Treatment is typically delivered by a paediatric cardiology team with PH experience.

Family Considerations

A child with PH affects the whole family. Schooling, activity restrictions, and the emotional load of managing a serious chronic condition are real, and paediatric PH centres usually include social work, psychology, and family support as part of the team. Genetic counselling is offered where heritable PAH is identified or suspected.

Prevention of Progression and Complications

True prevention of pulmonary hypertension is difficult, because many cases arise from underlying conditions that themselves cannot always be prevented. However, there are several things that can slow progression or reduce the risk of complications once PH is diagnosed:

• Consistent treatment of the underlying condition — whether that is heart failure, COPD, sleep apnoea, or connective tissue disease.
• Long-term anticoagulation in CTEPH, where standard.
• Avoiding medications and substances known to worsen PH, where alternatives exist.
• Vaccinations against respiratory infections.
• Prompt treatment of chest infections.
• Avoiding pregnancy in PAH unless this has been very carefully planned with a specialist team that includes a high-risk obstetrician.
• Regular monitoring with the specialist team, so that treatment can be stepped up before the right heart begins to fail.

When to Seek Urgent Care

Most pulmonary hypertension care is planned and ongoing, but certain situations need immediate attention:

• Sudden severe breathlessness, especially at rest.
• Chest pain that is severe or different from your usual pattern.
• Fainting or near-fainting.
• Coughing up blood.
• Rapid weight gain or sudden severe swelling.
• Confusion or significant change in alertness.
• Signs of infection — fever, productive cough, worsening breathlessness that are getting worse rather than better.

People on continuous prostacyclin infusions should also have a clear plan, agreed with their PH team, for what to do if the pump or line fails, because interruption of these medications can be dangerous.

Frequently Asked Questions

Is pulmonary hypertension the same as high blood pressure?

No. The high blood pressure most people are familiar with affects the arteries that carry blood from the heart to the body. Pulmonary hypertension affects the arteries that carry blood from the heart to the lungs. The causes, the treatments, and the medications used are different.

Can pulmonary hypertension be cured?

For most types of PH, the goal is long-term control rather than cure. Two important exceptions are chronic thromboembolic pulmonary hypertension (CTEPH), which can be cured in some people with pulmonary endarterectomy surgery, and PH caused by a reversible underlying condition (for example, certain medications, treatable valve disease, or severe untreated sleep apnoea), where treating the cause can substantially reduce the PH.

Will I need oxygen all the time?

Not necessarily. Oxygen therapy is recommended for people whose blood oxygen levels are low. Many people with PH do not need supplemental oxygen at rest but may need it during exertion, sleep, or air travel. Your specialist will measure your oxygen levels and decide what is appropriate.

Can I exercise with pulmonary hypertension?

Yes, in most cases, and supervised exercise rehabilitation tailored to PH has been shown in studies to improve symptoms and quality of life. The specific activities and intensity should be agreed with your specialist. Very heavy lifting and exercise that triggers severe symptoms are generally avoided.

Is pulmonary hypertension genetic?

A minority of cases of PAH are heritable, most often linked to changes in the BMPR2 gene. If there is a family history of PAH, or if PAH is diagnosed at a young age without an obvious cause, genetic counselling and testing may be offered. Most people with PH, however, do not have a hereditary form.

Why do I need to see a specialist centre?

Pulmonary hypertension is uncommon and the diagnosis, classification, and treatment options have become increasingly complex. Major society guidelines recommend that suspected and confirmed PH is evaluated at a centre with experience in the condition, because correct classification and appropriate treatment make a real difference to outcomes.

Can I travel by plane?

Many people with PH can fly, but the lower cabin oxygen levels at altitude can cause problems for some. Your specialist may recommend an assessment beforehand and arrange supplemental oxygen for the flight if needed. Travel to high-altitude destinations is a separate question and is often discouraged in significant PH.

Will my children get pulmonary hypertension?

If your PH is due to a non-heritable cause — left heart disease, lung disease, blood clots, or most cases of associated PAH — your children are not at increased risk of inheriting it. If a heritable form of PAH is identified, your children may be at higher risk and genetic counselling can help clarify what this means and what screening, if any, is appropriate.

How often will I need check-ups?

This depends on your type of PH, how stable you are, and whether treatment is being changed. Many stable patients are seen every three to six months. Those starting new medications or whose condition is not stable are seen more often. The specialist team will set the schedule.

Conclusion

Pulmonary hypertension is a serious but increasingly treatable condition. The most important steps after diagnosis are confirming which of the five groups of PH you have, treating the underlying cause where possible, starting appropriate PH-targeted therapy when indicated, and building a long-term partnership with a specialist team that monitors how the disease is responding.

Most people with pulmonary hypertension live with the condition for years and learn to manage it day to day. Medications and procedures have changed substantially over the past two decades, and many people now do better than would have been expected a generation ago. Staying engaged with the specialist team, taking treatment consistently, and learning to recognise change in your own body are the foundations of good long-term care.