A Guide to Pulmonary Hypertension for Patients

Pulmonary hypertension means the blood pressure inside the arteries that carry blood from the heart to the lungs is higher than it should be, which makes the right side of the heart work harder than normal and, over time, can damage it [3].

This page provides general information. It does not replace advice from a doctor or another qualified healthcare professional.

Key facts

Pulmonary hypertension is not the same as ordinary high blood pressure. It affects only the arteries going to the lungs, and a blood pressure cuff on the arm cannot detect it [3,5].
Around 1 in 100 people worldwide have some form of pulmonary hypertension, and it becomes more common with age [1,3].
There are five groups. Group 1, called pulmonary arterial hypertension, is rare. Groups 2 and 3, caused by heart and lung disease, are far more common and together make up most cases [1,3].
Since 2022 the condition has been defined as an average pressure in the lung arteries above 20 mmHg at rest, measured directly. The old threshold was 25 mmHg [1,2].
The usual first symptom is breathlessness during activity, and diagnosis is often delayed by more than two years because breathlessness has many other causes [1,8].
Most forms cannot be cured, though treatment helps a great deal, and one form caused by old blood clots can sometimes be cured by surgery [5,9].

What is pulmonary hypertension?

The heart’s left side pumps blood around the body. The right side pumps it a shorter distance into the lungs, through the pulmonary arteries. Pulmonary hypertension means the pressure in those arteries is too high, so the right side works harder. Over time its muscle thickens, weakens, and can fail [3,5].

It is not the same as ordinary high blood pressure. Ordinary high blood pressure affects the arteries supplying the rest of the body, and shows on an arm cuff. Pulmonary hypertension affects a separate set of arteries, does not show on a cuff, and is treated differently. Someone can have normal readings and still have it [3,5].

It is also not one disease. Doctors sort it into five groups, since the cause changes what helps and what harms [1,3]:

Group 1, pulmonary arterial hypertension (PAH). The small lung arteries narrow and stiffen. Rare.
Group 2, due to left heart disease. The most common group by far.
Group 3, due to lung disease or low oxygen. Common.
Group 4, due to blockages, usually old blood clots. Called chronic thromboembolic pulmonary hypertension, or CTEPH. Rare.
Group 5. Unclear, or several causes at once. Rare.

Since 2022 it has been defined as an average pressure above 20 mmHg at rest in those arteries, measured directly. The earlier threshold was 25 mmHg, so milder cases are now recognized [1,2].

How common is it?

It depends which form is counted.

Across all five groups, about 1% of the world’s population is estimated to have pulmonary hypertension, and it becomes more common over the age of 65 [1,3]. The United Kingdom figure has doubled in ten years, to about 125 cases per million diagnosed [1]. Left heart disease accounts for 65% to 80% of all cases, and lung disease, especially chronic obstructive pulmonary disease, comes next [1].

Group 1 is genuinely rare: in wealthier countries, about 6 new cases per million adults a year and 48 to 55 people per million adults living with it. Orphanet lists the idiopathic and inherited forms at 1 to 9 per 100,000 [1,7]. CTEPH is also rare, at 2 to 6 new cases and 26 to 38 people per million adults [1].

These figures come mostly from patient records in high-income countries, so they count diagnosed people rather than everyone affected. Comparable numbers for much of Africa, South America and Asia are not available [1].

What causes it?

For group 1, more than half of cases worldwide have no known cause, which doctors call idiopathic [3].

Some cases are inherited. A gene is a set of instructions inside cells, and a gene variant is a change in those instructions. The gene most often involved is BMPR2, in an autosomal dominant pattern: a change in one of the two copies a person carries is enough to raise the risk. Carrying it does not mean the condition will develop: estimated lifetime risk is about 20%, around 42% in women and 14% in men. Genetic counseling and yearly heart scans are advised for those who test positive and close relatives [1].

Group 1 is also linked to connective tissue disease, where the immune system attacks the body’s own supporting tissues. Between 5% and 19% of people with systemic sclerosis develop it, so yearly checks are advised [1]. Other links include HIV infection, heart differences from birth, and certain drugs and toxins [1].

Groups 2 to 4 have clearer causes: heart failure or valve disease, long-term lung conditions and low oxygen, and blood clots that did not clear [1,5]. Nothing a person did brings this on.

What are the symptoms?

The main symptom is breathlessness during activity, and it takes progressively less effort to bring on [1]. Other common symptoms are [1,5]:

tiredness and low energy
a racing or thumping heartbeat
chest pain or pressure
dizziness or feeling faint during activity
swelling, called edema, in the ankles, legs or tummy

Diagnosis is commonly delayed. Time from first symptoms to diagnosis is still more than two years on average, and most people are already at an advanced stage by then [1]. In a United Kingdom survey of 567 people, 48% waited a year or more and 40% saw four or more doctors first [8]. Breathlessness is very common and usually has another cause, so it is rarely the first thing considered.

When to seek urgent help. Call emergency services, 999 in the UK or 911 in the US, if you faint or black out, if chest pain does not settle within a few minutes, or if a racing heartbeat comes with chest pain or breathlessness. Contact your specialist team promptly if swelling worsens over days, if you gain weight quickly, or if you cough up blood [5].

How is it diagnosed?

Diagnosis usually happens in three steps [1,2].

Suspicion. A family doctor takes a history, examines the heart and lungs, checks blood pressure and blood oxygen, and arranges a heart tracing called an ECG and a blood test called NT-proBNP, which rises when the heart is strained [1,4].

Detection. An echocardiogram comes next: a painless ultrasound scan of the heart using a probe on the chest. It shows how the right side is coping and gives a level of probability, without confirming the diagnosis [1].

Confirmation. Right heart catheterization confirms it. A thin, flexible tube is passed through a vein in the neck or groin, under local anesthetic, into the right side of the heart and a pulmonary artery, to measure the pressure directly [1,5].

Finding the underlying cause matters as much as finding the raised pressure, since treatment differs between groups, so further tests usually include breathing tests, a CT scan, a scan looking for old clots, and a six-minute walk test [1,4]. Doctors also grade risk at diagnosis, using an estimated chance of dying within a year of under 5%, 5% to 20%, or over 20% [1].

How is it treated?

There is no cure for most forms, though treatment reduces symptoms and slows the condition [3,5]. What helps depends on the group.

Group 1. Most people at low or intermediate risk start two medicines together: an endothelin receptor antagonist, such as ambrisentan, bosentan or macitentan, plus a phosphodiesterase 5 inhibitor, such as sildenafil or tadalafil. Riociguat works on a related pathway. Prostacyclin medicines, including epoprostenol, treprostinil and selexipag, are added at higher risk, some by infusion. Sotatercept, an injection given under the skin every three weeks, was approved in the United States and the European Union in 2024, and its United States label was updated in 2025 after a study showed fewer hospital admissions, transplants and deaths [1,11,12]. Fewer than 1 in 10 people respond to a test done during catheterization and can instead use high-dose calcium channel blockers [1].

Groups 2 and 3. Here the priority is treating the underlying heart or lung condition well, with oxygen and pulmonary rehabilitation where needed. Guidelines state plainly that medicines approved for pulmonary arterial hypertension are not recommended in pulmonary hypertension due to left heart disease, and point to harm rather than benefit in some situations. In lung disease they are not recommended for milder cases, and ambrisentan and riociguat are specifically not recommended in some lung conditions because people did worse. Inhaled treprostinil is one exception, alongside interstitial lung disease [1].

Group 4 CTEPH, which can sometimes be cured. Surgery called pulmonary endarterectomy removes the old, hardened clot material, and is the treatment of choice where the blockages can be reached. It can restore close to normal blood flow, and for some people it is a cure: PHA UK states that about 96% of people survive the operation [9]. Where surgery is unsuitable, balloon pulmonary angioplasty threads a tiny balloon into the narrowed vessels and inflates it briefly, over several sessions. Riociguat is approved where surgery is not possible. Everyone with CTEPH needs lifelong blood-thinning treatment [1,5].

Supportive treatment. Diuretics, or water tablets, help fluid build-up, home oxygen is used when blood oxygen is low, and iron deficiency is worth correcting [1]. A lung transplant is considered when treatment is not working well enough, and availability differs between countries [1,5,9].

Living with pulmonary hypertension

Care is usually shared between a local team and a specialist center; the United Kingdom has eight [5]. Visits track symptoms, walking distance, blood tests and scans [1].

Advice on exercise has changed. Supervised exercise training is now recommended for people with pulmonary arterial hypertension who are stable on treatment, and it improves walking distance [1].

Pregnancy needs an early conversation. Guidelines recommend counseling at diagnosis and advice against becoming pregnant, since the risk to the mother is high. Several medicines must be stopped beforehand, and bosentan makes hormonal contraception less reliable [1]. Emotional and practical support is part of care: in the same survey, 63% of people reported financial worries [1,8].

Thinking about a clinical trial?

Clinical trials test whether a treatment works and is safe. Research in pulmonary hypertension is active, particularly in group 1 and CTEPH. Deciding whether to look into one is personal, and it helps to take it in steps.

1. Understand what the study is asking

Worth being clear on what a study involves:

what the researchers are trying to learn
what is being studied, and what it is compared with
how long it lasts, often six months to two years or more
what visits, tests and procedures are involved, including walk tests, blood tests and possibly a repeat right heart catheterization
how far you would need to travel, since studies run from specialist centers
the possible benefits, and the known and unknown risks
what happens when the study ends

2. Consider possible medical suitability

Every trial has rules about who can take part, called eligibility criteria. Some describe who can join, others who cannot. For a pulmonary hypertension study they might include a diagnosis confirmed by right heart catheterization, membership of a particular group, pressure measurements inside a set range, being moderately rather than severely limited by symptoms, a set six-minute walk distance, a stable dose of existing medicines beforehand, and reliable contraception for some treatments.

trialport’s medifit helps people consider information related to possible medical suitability. It does not diagnose a condition, confirm eligibility or replace formal screening by the study team.

Explore pulmonary hypertension clinical trials through trialport

3. Consider whether participation fits your life

Medical suitability is only part of the picture. A study can look right on paper and still be hard in practice:

the time each visit takes, and how many over a year or more
travel to a specialist center, who would come with you, and how tiring the journey is on a breathless day
work, school or caring responsibilities, and how much time off is realistic
support from family and friends
how you feel about injections, infusions or a repeat heart catheter test
whether you understand the study well enough to decide, and whether it feels right now

trialport’s readifit helps people reflect on their understanding, motivation, time, routines, support, emotions and practical arrangements.

4. Ask questions before deciding

Useful questions to put to a research team:

Why is this study being carried out, and what is already known?
Which group of pulmonary hypertension is it for, and does my diagnosis match?
What exactly would I need to do, and for how long?
What are the known risks, and what is still unknown?
Could I receive a placebo? A placebo is a dummy treatment with no active medicine, used so researchers can compare results fairly. Would I keep my usual treatment alongside it?
Would I need a repeat right heart catheterization, and if so, when?
Can I leave the study after joining, and what happens to my treatment if I do?
Are travel and other costs covered, and could I keep receiving the treatment afterward?

Taking part is voluntary. A person can ask questions, speak with people they trust and choose not to participate.

Search for clinical trials at app.trialport.com.

Current research

Changing how the lung arteries grow, rather than only widening them. Sotatercept works on activin signaling, a pathway involved in the thickening of the vessel walls, and is approved in the United States and the European Union [11,12].
Inhaled treatments. Seralutinib narrowly missed its main target in a phase 3 study reported in February 2026. It is not approved, and the company said it would discuss next steps with the United States regulator [13].
Earlier detection, since the delay to diagnosis is still over two years [1,8].
CTEPH, where longer-term balloon pulmonary angioplasty results are still being gathered [1,9].

Study status checked: 3 August 2026. Research moves quickly, so this list will date. For current information, search at app.trialport.com.

Support and further information

United States: the Pulmonary Hypertension Association runs support groups, peer mentors, a support line, financial guidance and accredited PH Care Centers [14].
United Kingdom: PHA UK has plain-language information, a Listening Line, online forums and help with benefits [9,10].
Europe: PHA Europe brings together 36 national member associations, working on awareness, standards of care and access to treatment [15].
Australia: Lung Foundation Australia has an information section on pulmonary arterial hypertension, with a booklet and talks [16].

Coverage elsewhere is thin. Many countries have a general heart or lung charity rather than a pulmonary hypertension organization, and the treating specialist center is then the best starting point.

Questions people often ask

Is pulmonary hypertension the same as high blood pressure?
No. It affects a different set of arteries, those going to the lungs, and an arm cuff cannot measure it [3,5].

Is it rare?
Group 1 is rare, at roughly 48 to 55 people per million adults. Pulmonary hypertension as a whole is not, affecting around 1% of people worldwide [1,3].

Can it be cured?
Most forms cannot. The exception is CTEPH, caused by old blood clots, where surgery to remove them can restore close to normal blood flow and for some people is a cure [5,9].

Do I really need a heart catheter test?
Yes. An echocardiogram can suggest pulmonary hypertension but cannot confirm it or show which group you are in [1].

Are the medicines the same for everyone?
No, and the difference is a safety point. Medicines developed for group 1 are not recommended in pulmonary hypertension caused by left heart disease, or for milder cases caused by lung disease [1].

Sources

Humbert M, Kovacs G, Hoeper MM, et al., on behalf of the ESC/ERS Scientific Document Group. 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension. European Heart Journal. 2022;43(38):3618. doi:10.1093/eurheartj/ehac237. https://academic.oup.com/eurheartj/article/43/38/3618/6673929 Accessed 3 August 2026.
Mukherjee D. 2022 ESC/ERS Guidelines for Pulmonary Hypertension: Key Points. American College of Cardiology, 30 August 2022. https://www.acc.org/latest-in-cardiology/ten-points-to-remember/2022/08/30/19/11/2022-esc-guidelines-for-pulmonary-hypertension-esc-2022 Accessed 3 August 2026.
National Heart, Lung, and Blood Institute. What Is Pulmonary Hypertension? Last updated 1 May 2023. https://www.nhlbi.nih.gov/health/pulmonary-hypertension Accessed 3 August 2026.
National Heart, Lung, and Blood Institute. Pulmonary Hypertension: Diagnosis. Last updated 24 March 2022. https://www.nhlbi.nih.gov/health/pulmonary-hypertension/diagnosis Accessed 3 August 2026.
NHS. Pulmonary hypertension: Overview, and Pulmonary hypertension: Treatment. Page last reviewed 2 May 2023. https://www.nhs.uk/conditions/pulmonary-hypertension/ and https://www.nhs.uk/conditions/pulmonary-hypertension/treatment/ Accessed 3 August 2026.
Centers for Disease Control and Prevention, National Center for Health Statistics. ICD-10-CM Web Application, FY2026 tabular list, category I27 Other pulmonary heart diseases. https://icd10cmtool.cdc.gov/ Accessed 3 August 2026.
Orphanet. Idiopathic/heritable pulmonary arterial hypertension. ORPHA:422. Last updated 11 June 2026. https://www.orpha.net/en/disease/detail/422 Accessed 3 August 2026.
Armstrong I, Billings C, Kiely DG, Yorke J, Harries C, Clayton S, Gin-Sing W. The patient experience of pulmonary hypertension: a large cross-sectional study of UK patients. BMC Pulmonary Medicine. 2019;19(1):67. doi:10.1186/s12890-019-0827-5. https://link.springer.com/article/10.1186/s12890-019-0827-5 Accessed 3 August 2026.
Pulmonary Hypertension Association UK. Surgical options. https://www.phauk.org/about-ph/treatment-for-ph/surgical-options/ Accessed 3 August 2026.
Pulmonary Hypertension Association UK. About PH. https://www.phauk.org/about-ph/ Accessed 3 August 2026.
Merck. U.S. FDA Approves Updated Indication for WINREVAIR (sotatercept-csrk) in Adults with Pulmonary Arterial Hypertension (PAH, WHO Group 1 Pulmonary Hypertension) Based on Phase 3 ZENITH Study. News release, 27 October 2025. https://www.merck.com/news/u-s-fda-approves-updated-indication-for-winrevair-sotatercept-csrk-in-adults-with-pulmonary-arterial-hypertension-pah-who-group-1-pulmonary-hypertension-based-on-phase-3-zenith-study/ Accessed 3 August 2026.
Merck. Merck Receives European Commission Approval for WINREVAIR (sotatercept) in Combination With Other Pulmonary Arterial Hypertension (PAH) Therapies, for the Treatment of PAH in Adult Patients With Functional Class II-III. News release, 26 August 2024. https://www.merck.com/news/merck-receives-european-commission-approval-for-winrevair-sotatercept-in-combination-with-other-pulmonary-arterial-hypertension-pah-therapies-for-the-treatment-of-pah-in-adult-patients-w/ Accessed 3 August 2026.
Gossamer Bio. Gossamer Bio Announces Topline Results from the Phase 3 PROSERA Study Evaluating Seralutinib in Pulmonary Arterial Hypertension. News release, 23 February 2026. https://ir.gossamerbio.com/news-releases/news-release-details/gossamer-bio-announces-topline-results-phase-3-prosera-study/ Accessed 3 August 2026.
Pulmonary Hypertension Association. Support. https://phassociation.org/living-with-ph/support/ Accessed 3 August 2026.
PHA Europe. Members of PHA Europe and Global and contact details. https://www.phaeurope.org/about-pha-europe/members-of-pha-europe-and-contact-details/ Accessed 3 August 2026.
Lung Foundation Australia. Pulmonary Arterial Hypertension. Last updated 3 August 2026. https://lungfoundation.com.au/lung-diseases/pulmonary-arterial-hypertension/ Accessed 3 August 2026.

Review information

Written by: trialport editorial team
Reviewed by: Keith Berelowitz, Founder and CEO, trialport
Reviewed on: 3 August 2026
Next review due: 3 August 2027
References last checked: 3 August 2026

Pulmonary hypertension: a plain-language guide