FAQ – PULMONARY HYPERTENSION

The following 20 questions and answers about pulmonary hypertension have been developed by Alliance for Pulmonary Hypertension volunteers and kindly reviewed by members of its Scientific Committee (1)

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Last update: January 12, 2026

Q 1 What is pulmonary hypertension?

“Pulmonary hypertension” refers to an abnormal elevation of pressure in the pulmonary arteries, confirmed by right heart catheterization (>20mmHg), a condition often found in advanced stages of heart and lung diseases.
At least 1% of the world’s population is estimated to be affected.
Some diseases where pulmonary hypertension is present are rare, while others are more common.
“Pulmonary arterial hypertension” (PAH) and “Chronic Thromboembolic Pulmonary Hypertension” (CTEPH) are rare diseases requiring specific medical and/or surgical/interventional solutions.
In the WHO (World Health Organization) classification, they fall respectively into Groups I and IV.
Groups II and III are associated with more common diseases, affecting respectively the heart and the lungs.
Group V includes ultra rare diseases.
Across all its forms, pulmonary hypertension is associated with vascular remodelling with obstruction, stiffening and vasoconstriction of the pulmonary vasculature.

Q 2 What are the symptoms of pulmonary hypertension?

Shortness of breath, which appears during exercise, e.g. walking up the stairs at a pace which was well tolerated earlier. It is not increased when lying flat.
Chest tightness on exertion
Fatigue
Rapid heartbeat
Swelling in the legs, ankles, feet or abdomen
Feeling of fainting or dizziness
Syncope (fainting) mainly on exertion
Hemoptysis (coughing up blood)
Chest pain

Q 3 Does pulmonary hypertension affect the lungs or the heart?

Both the heart and lungs are affected, in different ways.
The pulmonary artery is a main blood vessel that carries blood from the right side of the heart to small blood vessels in the lungs.
In the lungs, the blood is enriched with oxygen, circulated to the left side of the heart and then throughout the body.
In pulmonary hypertension, as a result of the disease process, the vessels of the lungs are narrowed and thus the blood flow from the heart to the lungs is slowed down
The heart then has to work harder to pump blood through the lungs.
Over time, the heart becomes fatigued, and this can lead to heart failure.

Q 4 Why is the blood flow slowed down in the pulmonary arteries?

In pulmonary arterial hypertension, an uncontrolled growth of cells in the walls of the pulmonary arteries causes them to narrow so it more difficult for the heart to pump blood through them.
In chronic thromboembolic pulmonary hypertension, the slowed blood flow is caused by the presence of old blood clots which cause occlusions/obstruction.
In other forms of pulmonary hypertension, it is a consequence of the underlying heart or lung diseases.

Q 5 Which are the rare forms of pulmonary hypertension?

We have seen in Q1 that there are various forms of pulmonary hypertension according to the WHO classification.
WHO Groups II and III concern common diseases affecting respectively the heart and lungs.
WHO Groups I (pulmonary arterial hypertension, PAH) and Group IV (chronic thromboembolic pulmonary hypertension, CTEPH) are rare forms. Group V includes ultra rare diseases.
Very often the term “pulmonary hypertension,” is also used for “pulmonary arterial hypertension”, to simplify, but, in reality, they are two very different things!
Pulmonary arterial hypertension can be subdivided into different types.
It is called “idiopathic” when the causes are unknown and “hereditary” when a genetic cause is identified.
It can also be “associated” with other pathologies (congenital heart disease, connective tissue disease, portal hypertension, HIV, use of anorexigenic drugs and substances of abuse).
“Associated” means there is a higher probability of developing pulmonary arterial hypertension in these populations compared to the general population.

Q 6 How can these rare forms of pulmonary hypertension be detected?

Being rare, pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension are not frequently seen/managed by medical professionals.
Sometimes the symptoms, which are non-specific, can be confused with those of more common diseases (e.g. asthma) and even anxiety and depression.
For these reasons there can be considerable delays in arriving at a correct diagnosis.
This is a big problem because the sooner patients are initiated on therapy, the better the clinical outcomes.
A general practitioner or a specialist (pulmonologist, cardiologist, rheumatologist…) can formulate a suspicion of pulmonary hypertension.
An echocardiogram can give a first indication of the presence of pulmonary hypertension.
However, more specialised investigations are necessary for the final diagnosis

Q 7 What happens after there is a suspicion of pulmonary hypertension?

The patient should be referred to a specialized center for further diagnostics.
A precise diagnostic process (algorithm) is laid out in the latest pulmonary hypertension guidelines.
There is a difference between the diagnostic process for pulmonary arterial hypertension and for chronic thromboembolic pulmonary hypertension.
The diagnostic process allows the identification of the exact form of pulmonary hypertension that the patient is suffering from.
This, in turn, is essential in order to choose the most appropriate management option.

Q 8 Why should patients be referred to a specialist center?

The complexity of the disease requires a holistic and integrated approach.
This underlines the importance of a multidisciplinary medical team, as stated in the latest pulmonary hypertension guidelines.
The confirmation of the diagnosis requires complex investigations: one of these is right heart catheterization (RHC), a medical procedure that involves inserting a very fine tube (catheter) into the heart via a large vein to measure the pressure directly in the right side of the heart and in the pulmonary artery.
Choosing the most appropriate therapeutic strategy requires specific skills and experience.
Some of the drugs are complex to manage and require training and continuous assistance for both the patient and family members.
Only an expert center is able to guarantee access to, and proper management, of all available therapeutic and surgical options.
Only expert centres have the possibility to include patients in clinical trials.
It is very important to attend regular follow-up visits at the expert centre to monitor the evolution of the disease and make any necessary changes to the therapy.

Q 9 What therapies are available for pulmonary arterial hypertension?

In Europe, eleven medical therapies have been approved pulmonary arterial hypertension.
These belong to four different “classes”: each targets the condition from a different angle; this means they can be combined for greater effectiveness (see below at Q10).
Within three of these “classes” there are two or more drugs: in medicine it is good to have alternatives, as patients can respond to and tolerate the same drug differently, and within a given class of drugs there may be more potent molecules than others.
Some of these drugs are for oral administration.
Others are for continuous 24/7 infusion, via portable “pumps”, subcutaneously or intravenously.
Still others are for inhalation, via portable nebulizers.
Depending on the individual case, drugs may also be prescribed to promote diuresis and heart contractility, and to fluidify the blood.
In so-called “vasoactive responders”, persons who respond well to an acute “vasoreactivity test”, the therapeutic approach is different, as calcium channel blocker therapy has proven to be very effective.
Oxygen therapy is indicated only in a limited number of cases.

Q 10 Which are the different “classes” of pulmonary hypertension drugs?

1. Endothelin Receptor Antagonists (ERAs) block the action of endothelin-1, a substance that causes constriction of blood vessels in the lungs (ambrisentan, bosentan and macintentan, all oral medications)
2. Phosphodiesterase-5 inhibitors (PDE-5 inhibitors) and soluble guanylate cyclase stimulators (sGC stimulators) both enhance signalling through cyclic GMP (cGMP), which helps relax and dilate the pulmonary blood vessels. PDE-5 inhibitors work by inhibiting the PDE-5 enzyme that breaks down cGMP, while sGC stimulators increase the production of cGMP by stimulating soluble guanylate cyclase. These include the oral medications sildenafil and tadalafil (PDE-5 inhibitors) and riociguat (an sGC stimulator).
3.A single pill combining an endothelin receptor antagonist and a phosphodiesterase-5 inhibitor (macintentan and tadalafil) was approved in 2024.
4. Prostacyclin therapies include prostacyclin analogues (prostanoids), which are synthetic forms of prostacyclin, a naturally occurring substance that dilates blood vessels and inhibits vascular remodeling. These include iloprost, treprostinil, and epoprostenol, administered by inhalation or continuous infusion. In addition, selexipag is an oral prostacyclin IP receptor agonist that mimics prostacyclin signalling but is not a prostacyclin analogue.
5.Another prostanoid for oral administration, beraprost, is not approved in Europe.
6. Activin signaling inhibitors address the underlying mechanisms that cause the uncontrolled proliferation of cells in the pulmonary arteries. The first drug belonging to this class (sotatercept) was approved in 2024.

Q 11 What medical therapies are available for chronic thromboembolic pulmonary hypertension?

Approved medical therapies include the soluble guanylate cyclase stimulator riociguat (oral) and the prostanoid treprostinil (24/7 infusion)
Combination therapy, including phosphodiesterase-5 inhibitors and endothelin receptor antagonists, is common practice in patients with chronic thromboembolic pulmonary hypertension with severe haemodynamic compromise but are used off-label, as their efficacy in inoperable patients has not been proven by randomised controlled trials or registry data.
Lifelong therapeutic anticoagulation is recommended.

Q 12 What are “infusion pumps” and when and how are they used?

Two drugs for pulmonary arterial hypertension (epoprostenol and treprostinil) require the use of a continuous 24/7 infusion pump.
The pumps work a bit like an intravenous drip.
In an IV drip, the liquid flows downward due to gravity.
With the pump, on the other hand, the drug is “pushed” upwards. The rate of infusion can be set up on the pump according to individual patient needs.
In intravenous therapy, the drug is infused through the pump into the pulmonary circulation via a very thin catheter inserted into the subclavian vein in the chest.
In subcutaneous therapy, the drug is infused through a very thin catheter inserted into the subcutaneous tissue, usually in the abdominal area.
Recent innovations include implantable pump systems for prostacyclin delivery.

Q 13 Who decides which drugs are prescribed to patients?

A pulmonary hypertension expert or the medical team at the pulmonary hypertension center will evaluate the best treatment option, together with the patient.
Depending on the form and stage of pulmonary hypertension, an initial therapy is chosen, usually oral.
Subsequently, a second drug from a different class than the first can be added.
In some cases, combination therapy with two drugs is started right from the beginning
If the two drugs are not effective enough, a third drug from a different class than the other two can be added (triple combination therapy).

Q 14 What are the surgical options in pulmonary arterial hypertension?

Currently, patients with pulmonary arterial hypertension who do not respond satisfactorily to the most potent therapy are put on the waiting list for lung transplantation or heart-lung transplantation.
In most transplant centers double lung transplantation is performed.
Heart-lung block transplantation is now reserved for patients with pulmonary arterial hypertension and complex congenital heart defects that cannot be corrected.

Q 15 What are the surgical/interventional options in chronic thromboembolic pulmonary hypertension?

A multimodal approach for chronic thromboembolic pulmonary hypertension was introduced by the latest pulmonary hypertension guidelines.
This approach may include combinations of pulmonary endarterectomy surgery (PEA), balloon pulmonary angioplasty (BPA), and medical therapies.
Pulmonary endarterectomy is the surgical treatment of choice for patients with accessible pulmonary artery thromboembolic obstructions. In this procedure, the organized clot material is removed from the pulmonary arteries, relieving the obstruction.
Balloon pulmonary angioplasty has become an established treatment for selected patients with inoperable chronic thromboembolic pulmonary hypertension or persistent/recurrent pulmonary hypertension after pulmonary endarterectomy. It involves using a balloon catheter to open the narrowed blood vessels in the lungs, which helps improve blood flow and reduces symptoms.
Both pulmonary endarterectomy and balloon pulmonary angioplasty are therapeutic options of high efficacy.

Q 16 Are any new drugs expected for pulmonary arterial hypertension in the near future?

A number of clinical trials on potential new drugs are currently underway, some of which are in an advanced stage of development or registration with regulatory authorities.
Seralutinib, a tyrosine kinase inhibitor, a new class of drugs, is currently being investigated in a Phase 3 trial.
New modes of administration of existing drugs, oral and inhaled, as well as new infusion pumps and nebulizers, are also under study.

Q 17 Are any new drugs expected for chronic thromboembolic pulmonary hypertension in the near future?

Clinical trials on potential drugs are currently underway.

Q 18 Are there any studies on new techniques for lung transplant?

There is ongoing research on different aspects of transplant, in different stages of development.
Ex-vivo lung perfusion systems have emerged as a promising advancement, allowing for the reconditioning and evaluation of marginal donor lungs, thus expanding the donor pool.
Regenerative medicine aims to repair or regenerate damaged lung tissue via stem cell therapies, immunomodulation therapy, and tissue engineering.

Q 19 Are there any social benefits and entitlements for patients?

Healthcare costs: Many countries offer healthcare costs’ exemptions for various tests and medications to patients.
Disability laws and benefits: Benefits related to civil incapacity and other support laws differ globally.
Work: Certain jobs may be too strenuous or pose infectious or toxic risks, making them unsuitable for patients. It is advisable to obtain clinical reports to present to employers or relevant authorities to secure a more suitable job.
Since regulations and practices vary by region, it is essential to seek precise information from local welfare offices. Transplant center social workers can also provide guidance and advice tailored to individual circumstances.
Patient associations can provide information and assist with applications for benefits.

Q 20 Who should I contact after having received a diagnosis of pulmonary hypertension?

Your general practitioner for initial medical information and any procedures for social benefits.
Your pulmonary hypertension specialists, both doctors and nurses, for in-depth information on the disease and therapies.
The municipality of residence for other forms of assistance.
Your local patient association for information, opportunities to meet other patients and families, legal and administrative advice, financial and organizational support, advocacy for patients’ rights, professional assistance programs, other support services.
Patient associations for diseases related to pulmonary hypertension (congenital heart diseases, systemic sclerosis, etc.), or associations of patients who have received or are awaiting lung or heart-lung transplants.

Footnote (1): These 20 questions are based on the content of the booklet by AIPI, Italian Pulmonary Hypertension Association, titled “Cos’è l’ipertensione arteriosa polmonare? Una breve guida“. As this booklet was mainly about pulmonary arterial hypertension, additional information about chronic thromboembolic pulmonary hypertension has been added, and further edits were suggested by the Alliance for Pulmonary Hypertension’s Scientific Committee who kindly reviewed the entire content.

Sources:

Corrigendum to: 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension: Developed by the task force for the diagnosis and treatment of pulmonary hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS). Endorsed by the International Society for Heart and Lung Transplantation (ISHLT) and the European Reference Network on rare respiratory diseases (ERN-LUNG) Free European Heart Journal, Volume 44, Issue 15, 14 April 2023, Page 1312, https://doi.org/10.1093/eurheartj/ehad005Published: 23 February 2023
Mocumbi, A., Humbert, M., Saxena, A. et al. Pulmonary hypertension. Nat Rev Dis Primers 10, 1 (2024). https://doi.org/10.1038/s41572-023-00486-7, Accepted27 November 2023, Published 04 January 2024, Version of record 04 January 2024, DOI https://doi.org/10.1038/s41572-023-00486-7