---
title: Pulmonary hypertension
description: What pulmonary hypertension is, why the pressure in the pulmonary artery rises, how it is measured, which treatment approaches the clinical guidelines describe, and when to call an ambulance.
type: disease
aliases:
  - PH
  - PAH
  - pulmonary arterial hypertension
sources:
  - tier: guideline
    org: minzdrav-rf
    title: Легочная гипертензия, в том числе хроническая тромбоэмболическая легочная гипертензия
    year: 2024
    doi: 10.15829/1560-4071-2024-6161
    url: https://doi.org/10.15829/1560-4071-2024-6161
  - tier: guideline
    org: esc
    title: 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension
    year: 2022
    doi: 10.1183/13993003.00879-2022
    url: https://doi.org/10.1183/13993003.00879-2022
  - tier: reference
    org: msd-manuals
    title: Pulmonary Hypertension
    year: 2024
    url: https://www.msdmanuals.com/professional/pulmonary-disorders/pulmonary-hypertension/pulmonary-hypertension
sources_checked: 2026-10-12
review: null
---

Pulmonary hypertension (PH) is a condition in which the pressure in the <Structure id="pulmonary-trunk">pulmonary artery</Structure> is raised: the mean pressure in it at rest is above 20 mm Hg. It is measured during right heart catheterisation.<Cite n={[1, 2, 3]} /> Normally the mean pressure in the pulmonary artery at rest is 20 mm Hg or less.<Cite n={1} />

PH is usually not a disease in its own right but a consequence of other heart and lung diseases; it is only very rarely a disease in itself.<Cite n={[1, 3]} /> PH affects about 1% of people worldwide, and it is more common in people over 65.<Cite n={[1, 2]} />

<Diagram name="pulmonary-hypertension">
  <p slot="normal">
    Normally the mean pressure in the pulmonary artery at rest is 20 mm Hg or less.<Cite n={1} />
    The normal picture shows none of the changes that appear in pulmonary arterial hypertension:
    the walls of the small pulmonary arteries are not thickened and their lumen is not narrowed,
    the wall of the <Structure id="right-ventricle">right ventricle</Structure> is not thickened and its cavity is not enlarged.<Cite n={[1, 3]} />
  </p>
  <p slot="disease">
    In pulmonary arterial hypertension (PAH) the walls of the small pulmonary arteries and
    arterioles thicken and the lumen narrows, sometimes until it is almost closed. The resistance
    of the lung vessels rises and the right ventricle works under strain.<Cite n={1} /> The mean
    pulmonary artery pressure at rest is above 20 mm Hg.<Cite n={1} /> Over time the wall of the
    right ventricle thickens, and later the ventricle dilates.<Cite n={3} /> The diagram shows the
    mechanism of PAH. In other groups of PH the cause is different: diseases of the left side of
    the heart, lung diseases or lack of oxygen, blockage of the pulmonary arteries (most often by
    thrombotic material), and in group 5 the mechanisms are unclear or mixed.<Cite n={1} />
  </p>
</Diagram>

## Why it happens

<Patient>

PH most often develops because of diseases of the left side of the heart, such as [heart failure](../heart-failure/) or valve disease.<Cite n={[1, 2]} /> Lung diseases come second, especially chronic obstructive pulmonary disease (COPD).<Cite n={2} />

In diseases of the left side of the heart, raised pressure in the left chambers is passed backwards onto the lung veins. In lung diseases, the lung vessels narrow in response to a lack of oxygen in the blood, and then their walls are remodelled.<Cite n={1} />

In chronic thromboembolic PH (CTEPH) the pulmonary arteries are blocked for a long time by thrombotic material.<Cite n={1} /> Doctors think of it when breathlessness does not go away after a [pulmonary embolism](../pulmonary-embolism/) (PE), but a quarter of patients have never had a known PE.<Cite n={[1, 2]} /> More in the article on [CTEPH](../chronic-thromboembolic-pulmonary-hypertension/).

Pulmonary arterial hypertension (PAH) is a rare disease in which the small pulmonary arteries themselves are affected.<Cite n={[1, 3]} /> Sometimes no cause can be found. PAH can also be inherited, or linked to certain drugs and toxins, connective tissue diseases, HIV infection, liver disease or congenital heart defects.<Cite n={[1, 2]} />

</Patient>

<Student>

The Russian Ministry of Health guideline defines PH as a haemodynamic and pathophysiological condition with a mean pulmonary arterial pressure (mPAP) > 20 mm Hg at rest measured by transvenous cardiac catheterisation, that is, right heart catheterisation (RHC). Pre-capillary PH is mPAP > 20 mm Hg, pulmonary arterial wedge pressure (PAWP) ≤ 15 mm Hg and pulmonary vascular resistance (PVR) > 2 Wood units; in post-capillary PH, PAWP is > 15 mm Hg.<Cite n={[1, 2]} />

The clinical classification has five groups: 1, PAH; 2, PH associated with left heart disease; 3, PH associated with lung diseases and/or hypoxia; 4, PH associated with pulmonary artery obstructions, including CTEPH; 5, PH of unknown and/or mixed origin.<Cite n={[1, 2]} /> Unlike the 2022 ESC/ERS guidelines, the Russian guideline keeps the subgroup of complex congenital heart disease in group 5.<Cite n={1} />

PAH is based on remodelling of the pulmonary arteries and arterioles: intimal hyperplasia, hypertrophy and hyperplasia of the media and adventitia with perivascular inflammation and fibrosis, up to subtotal obliteration of the lumen, a rise in PVR and right ventricular (RV) overload.<Cite n={1} /> The key step is endothelial dysfunction: an excess of vasoconstrictors (endothelin-1, thromboxane A2, serotonin) and a lack of vasodilators (nitric oxide, prostacyclin).<Cite n={[1, 3]} /> In familial PAH, mutations in the BMPR2 gene are found in 75% of cases.<Cite n={[1, 3]} />

In CTEPH, besides obstruction of the elastic pulmonary arteries by thrombotic material, distal pulmonary vasculopathy plays a role.<Cite n={1} /> Whatever the cause, PH leads to RV pressure overload and dysfunction; RV function is the main factor determining prognosis.<Cite n={[1, 2]} />

</Student>

<HeartModel highlight={['pulmonary-trunk', 'right-ventricle']} />

## Symptoms

<Patient>

In the early stages, symptoms appear during physical activity.<Cite n={1} /> The main one is breathlessness on exertion that gets worse over time. There may also be tiredness, weakness, dizziness and palpitations.<Cite n={[1, 2, 3]} /> These symptoms are non-specific, so the diagnosis is often made late: according to the ESC, more than two years pass from the first symptoms to the diagnosis.<Cite n={[1, 2]} />

Chest pain, dizziness and fainting during exertion are very unfavourable signs.<Cite n={[1, 3]} /> Swollen legs, a swollen abdomen and swollen, pulsating neck veins point to severe failure of the right side of the heart and advanced disease.<Cite n={1} />

</Patient>

<Student>

The cardinal symptom is dyspnoea on progressively minor exertion; early symptoms are mainly linked to RV dysfunction and occur on exertion.<Cite n={[1, 2]} /> Atypical chest discomfort and exertional presyncope indicate more severe disease.<Cite n={3} /> In late stages, syncope and signs of right heart failure appear: leg oedema, hepatomegaly, ascites, pulsation of the neck veins.<Cite n={[1, 3]} />

In long-standing PAH, anginal chest pain may occur.<Cite n={1} /> In the Russian registry, the median time from symptom onset to diagnosis confirmed by catheterisation is 52.8 months in PAH and 14 months in CTEPH.<Cite n={1} />

</Student>

## How it is diagnosed

<Patient>

The doctor asks about symptoms and illnesses, including those in relatives, examines you, and arranges an ECG and a blood test for natriuretic peptide (BNP or NT-proBNP).<Cite n={2} /> A normal ECG does not rule out PH.<Cite n={2} />

The main screening test is an ultrasound scan of the heart, [echocardiography](../../diagnostic/echocardiography/): from it the doctor estimates how likely PH is.<Cite n={[1, 2]} /> Echocardiography cannot confirm the diagnosis. That needs right heart catheterisation: a thin catheter is passed through a vein into the heart and the pulmonary artery, and the pressure is measured.<Cite n={[1, 2, 3]} /> It is recommended that this is done in an expert centre.<Cite n={1} />

Then the cause is looked for: lung function is tested, a lung scan is done so as not to miss CTEPH, and a chest CT scan may be arranged.<Cite n={[1, 2]} /> If breathlessness persists after three months of anticoagulant treatment for a PE, echocardiography is needed to assess the probability of PH.<Cite n={1} />

</Patient>

<Student>

Typical ECG signs are right axis deviation, P pulmonale, signs of RV hypertrophy and strain, right bundle branch block and QTc prolongation; a normal ECG does not exclude PH.<Cite n={[1, 2]} />

Transthoracic echocardiography is the first-line, non-invasive investigation in suspected PH. Based on the peak tricuspid regurgitation velocity and additional echocardiographic signs, the probability of PH is graded as low, intermediate or high.<Cite n={[1, 2]} /> Only right heart catheterisation confirms the diagnosis; it is the gold standard for diagnosing and classifying PH and should be performed in an expert centre.<Cite n={[1, 2]} />

Ventilation/perfusion lung scintigraphy is recommended to exclude CTEPH.<Cite n={[1, 2]} /> CTEPH should be considered when dyspnoea or functional limitation persists after PE.<Cite n={2} />

</Student>

## How it is treated

<Patient>

Treatment depends on the group of PH.<Cite n={1} /> If PH is caused by a disease of the left side of the heart or of the lungs, the main thing is to treat that disease; in lung disease with low blood oxygen, long-term oxygen treatment is added.<Cite n={[1, 2, 3]} /> Special PAH medicines are not used when PH is caused by diseases of the left side of the heart.<Cite n={[1, 3]} />

There is no medicine yet that cures PH. In PAH a specialist chooses special medicines: they lower the resistance of the lung vessels, reduce breathlessness and improve exercise tolerance.<Cite n={1} /> If medicines do not help, a lung transplant or a heart–lung transplant is considered.<Cite n={[1, 3]} /> Diuretics (water tablets) are used for swelling, and oxygen when needed.<Cite n={[1, 3]} />

In CTEPH the main treatment is an operation that removes thrombotic material from the pulmonary arteries (pulmonary endarterectomy).<Cite n={[1, 2, 3]} /> If surgery is not possible or PH remains after it, the narrowed arteries are widened with a balloon passed through a catheter (balloon pulmonary angioplasty). The methods are often combined with each other and with medicines.<Cite n={[1, 2]} /> Medicines that reduce blood clotting are prescribed for life in CTEPH.<Cite n={[1, 2]} />

Pregnancy is not recommended for women with PH: it carries a high risk of death for the mother.<Cite n={1} /> People with PAH should not push themselves during exercise to the point of severe breathlessness, dizziness or fainting; the Russian guideline advises discussing flu and pneumococcal vaccination with the doctor and avoiding high altitudes.<Cite n={[1, 3]} /> The doctor decides which treatment is needed.

</Patient>

<Student>

In PH due to left heart disease, the main strategy is optimising treatment of the underlying disease; PAH-specific therapy is not recommended (in the Russian guideline, post-capillary PH is a contraindication to it).<Cite n={[1, 2]} /> In PH due to lung disease, treatment starts with optimising therapy of the underlying disease, including oxygen therapy and, where indicated, non-invasive ventilation.<Cite n={[1, 2]} />

Supportive therapy includes anticoagulants, diuretics, cardiac glycosides and oxygen therapy.<Cite n={1} /> Calcium channel blockers are used in idiopathic and heritable PAH and in PAH associated with drugs or toxins only if the vasoreactivity test is positive. Otherwise, five classes of PAH-specific drugs are used: endothelin receptor antagonists, phosphodiesterase 5 inhibitors, soluble guanylate cyclase stimulators, prostacyclin analogues and prostacyclin receptor agonists.<Cite n={[1, 2]} /> These drugs prolong survival and reduce the need for hospital admission.<Cite n={1} /> If combination therapy fails, bilateral lung transplantation or heart–lung transplantation is recommended.<Cite n={1} />

In CTEPH, pulmonary endarterectomy is the treatment of choice for accessible lesions; operability is assessed by a multidisciplinary team at an expert centre.<Cite n={[1, 2]} /> In inoperable CTEPH or residual PH after surgery, balloon pulmonary angioplasty is considered; surgical, interventional and medical treatments are often combined.<Cite n={[1, 2]} /> Anticoagulation in CTEPH is lifelong.<Cite n={[1, 2]} />

</Student>

## When to call an ambulance

The Russian Ministry of Health guideline lists complications of PAH that need emergency hospital admission: recurrent fainting, pulmonary haemorrhage, acute PE, rhythm or conduction disturbances that compromise the circulation, and severe right ventricular failure with low blood pressure or reduced urine output.<Cite n={1} />

Call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK) if a person with PH faints, starts coughing up blood, becomes rapidly more breathless or has palpitations and feels faint.<Cite n={[1, 2]} /> As with any heart condition, call an ambulance for fainting, chest pain or severe shortness of breath: this is the site's general safety rule, repeated at the bottom of every page.

<Quiz />