PULMONARY HYPERTENSION

✓ Medically ReviewedDISEASEID: MDBT0062🚨 TRIAGE: URGENTICD-10: I27.20

📖

Definition

CLINICAL DEFINITION

Pulmonary hypertension is raised pressure in the lung circulation (lung vessel system). Haemodynamics (pressure and flow measures) mark it as mean artery pressure above 20 mmHg at rest. Proof needs right heart catheterisation (vein to heart pressure study). It is a syndrome (linked set of signs) with heart, lung and clot causes. Untreated disease strains the right ventricle (right pump chamber) into failure.

IN PLAIN ENGLISH

Lung vessels carry blood at too high pressure. The right heart must push much harder to move blood. This causes breathlessness and tiredness with effort. Ankles may swell as the right heart weakens. Special heart tests confirm it and find the cause.

COMMON MISCONCEPTION / WHAT IT DOES NOT MEAN

Pulmonary hypertension is not body hypertension (high pressure in body arteries). It is not asthma alone with reversible wheeze and normal pressures. It is not left heart failure alone without proven lung pressure rise. It is not a fresh clot alone without chronic pressure rise. Catheter proof of raised mean pressure is needed.

🔤

Word Breakdown

hyper-

=excessive or above normal

pulmon- / tens-

=lung / tension (pressure)

-ion

=state or condition of

Literal Meaning: state of excessive pressure in the lung circulation

🏷️

Abbreviations

PH=Pulmonary hypertension - high pressure in lung vessels

PAH=Pulmonary arterial hypertension - Group 1 disease of small lung arteries

CTEPH=Chronic thromboembolic pulmonary hypertension - Group 4 disease from old clots

mPAP=Mean pulmonary arterial pressure - average lung artery pressure at catheter test

PAWP=Pulmonary arterial wedge pressure - left heart filling estimate splitting pre and post capillary disease

🔄

Synonyms & Variants

Pulmonary hypertensive disease›Pulmonary vascular hypertension›

🎯

Category-Specific Context

Pulmonary hypertension is a Disease because it is a lasting syndrome with set pressure criteria and vessel course. It spans five WHO cause groups with distinct therapy. Staging by cause and risk matters more than the pressure number alone. Care targets the cause plus vessels and right heart.

🏥

Clinical Context & Usage

CLINICAL SETTINGS

Cardiology ClinicRespiratory ClinicPulmonary Hypertension Referral CentrePrimary Care for follow-upRheumatology ClinicHigh-risk Obstetrics Clinic

USAGE & DOCUMENTATION NOTES

Use the term after echo (heart ultrasound) suggests raised pressures and catheter confirms them. Always state WHO group and functional class (symptom level). Do not use it for brief pressure rise in acute illness alone. Record right heart signs at each visit.

🔬

Primary Causes & Pathophysiology

PATHOPHYSIOLOGY

Healthy lung vessels run at low pressure with spare capacity. Disease brings vessel tightening and lining failure. Smooth muscle growth, inflammation and clotting narrow small arteries. Fibrosis (scarring) stiffens walls and cuts flexibility. Resistance rises so pressure must rise to keep flow. The right ventricle thickens then widens and fails.

PRIMARY CAUSES

Idiopathic pulmonary arterial hypertension

Small artery wall thickening narrows vessels without known trigger. Resistance rises and strains the right heart.

Heritable disease with BMPR2 gene change (growth signal defect)

Faulty growth signals drive lining failure and muscle growth. Small arteries narrow and stiffen from early life.

Connective tissue disease such as systemic sclerosis (autoimmune stiffening disorder)

Immune inflammation plus scarring injures vessels. Widening fails and resistance climbs.

Congenital shunt such as septal defect (hole with extra lung flow)

Years of high flow injure lining and remodel walls. Flow later reverses with blue colour from low oxygen.

Left heart disease including failure and mitral or aortic valve disease

High left filling pressure backs up into lung veins and arteries. Congestion plus reactive remodelling lifts pressures.

Lung disease and low oxygen including COPD (airflow blockage) and interstitial disease (lung scarring) and sleep apnoea (night breathing pauses)

Low oxygen tightens vessels while vessel loss and wall thickening fix resistance high. Gas exchange worsens in parallel.

Chronic thromboembolic disease

Old organised clots block major vessels. Small vessel disease spreads resistance beyond blocked parts.

Multifactorial Group 5 disease including sickle cell disease (red cell sickling disorder) and sarcoidosis (granuloma inflammation)

High output, anaemia (low red cells), clotting and inflammation combine. Pressures rise through mixed paths.

💊

Drug-Induced Causes

💊 Fenfluramine and dexfenfluramine appetite suppressants ↗

Mechanism: Serotonin linked lining injury with muscle growth narrowing small arteries

→ Stop drug for good, refer urgently to hypertension centre for targeted therapy and follow-up

💊 Dasatinib leukaemia therapy ↗

Mechanism: Toxic lining injury with immune remodelling lifting resistance, often partly reversible

→ Stop dasatinib with oncology input, switch cancer therapy, refer to hypertension centre and track pressures

💊 Methamphetamine and other stimulants ↗

Mechanism: Repeat tightening plus toxic remodelling of small arteries

→ Stop exposure with addiction support, refer for vessel widening therapy if disease persists

💊 Alkylating agents including mitomycin and cyclophosphamide ↗

Mechanism: Vein and small vessel injury causing veno-occlusive (vein blocking) pattern with congestion

→ Stop agent with oncology input, refer urgently, avoid vessel widening drugs without expert plan

🌍

Epidemiology

Prevalence:Pulmonary hypertension is uncommon by catheter proof in the community. Left heart related Group 2 leads hospital cases. Lung related Group 3 leads respiratory clinic cases. Arterial Group 1 is rare with female excess. Clot related Group 4 is uncommon but under-recognised.

Age Group:All ages can be affected across groups. Idiopathic (unknown cause) and heritable forms peak in young to middle adults. Left heart and lung related forms dominate in middle and older adults. Shunt related forms present in children and young adults.

Geographic Distribution:Pulmonary hypertension occurs worldwide in all regions. Schistosomiasis (parasite infection) related disease clusters in endemic tropical zones. High altitude disease clusters in mountain populations. Referral and testing access shape recorded patterns.

Red Flags & Triage ★

TRIAGE LEVEL

🚨 URGENT

DO NOT MISS — LIFE-THREATENING PRESENTATIONS

Left heart disease as the commonest cause needing different therapy
Chronic clot disease curable by surgery in selected cases
Connective tissue, HIV and liver triggers needing tests
Drug causes needing withdrawal
Pregnancy risk needing urgent counselling

URGENT EVALUATION TRIGGERS

Faint or near-faint, mainly on effort
Rest chest pain or severe breathlessness
Coughing blood
Leg swelling with belly fluid and weight gain
Low pressure, fast heart or low oxygen
Pregnancy or planned pregnancy
Worse functional class despite therapy

Contraindications & Precautions

CONTRAINDICATIONS

Pregnancy is strongly discouraged owing to high maternal risk
Oestrogen combined contraception is avoided owing to clot risk
High altitude travel without oxygen planning
Endothelin blockers in pregnancy owing to birth defect risk

SPECIAL PRECAUTIONS

Plan anaesthesia and surgery with expert centre owing to crisis risk
Avoid dehydration and excess water loss owing to filling dependence
Avoid strong vessel tightening drugs without supervision
Track liver and blood counts on endothelin blockers
Update vaccines and treat infections promptly

Complications

DOWNSTREAM CLINICAL COMPLICATIONS

Right ventricular failure
Faint and near-faint on effort
Atrial arrhythmia
Coughing blood from bronchial vessels
In-situ artery clotting
Low oxygen with blue colour
Liver congestion with belly fluid
Sudden cardiac death

🔀

Confused With (LASA & DDx) ★

LEXICAL (LASA) — SIMILAR NAMES

Systemic hypertension

Shares hypertension in name but is high body artery pressure, not lung artery pressure

Portal hypertension

Shares hypertension in name but is high liver portal vein pressure, not lung artery pressure

Pulmonary hypotension

Differs by prefix but is low lung pressure from low output, the opposite state

CLINICAL DIFFERENTIAL DIAGNOSES (DDx)

Left heart failure with venous congestion

Key Distinguishing Feature: Wedge pressure above 15 with crackles and enlarged left atrium points to left heart cause

COPD without hypertension

Key Distinguishing Feature: Airflow block dominates with milder echo pressures and normal catheter pressures

Asthma

Key Distinguishing Feature: Reversible wheeze with normal right pressures and no right strain

Acute pulmonary embolism

Key Distinguishing Feature: Sudden pleuritic pain and fast heart with fresh clot, not chronic remodelling

Interstitial lung disease

Key Distinguishing Feature: Restrictive blow test with fibrosis on high resolution CT and marked low oxygen

Athletic deconditioning

Key Distinguishing Feature: Effort fatigue with normal echo, normal BNP (heart stress marker) and normal catheter study

💎

Clinical Pearls

💎

Confirm with catheter and split pre from post capillary disease using wedge pressure. Echo estimates pressure but cannot replace catheter proof.

💎

Order ventilation-perfusion scan in every new case to catch chronic clot disease. Surgery can cure selected CTEPH (clot group) cases.

💎

Counsel firmly against pregnancy with effective contraception and referral. Pregnancy can be fatal when pressures are severe.

💎

Use risk tables with walk distance, class, BNP (stress marker) and imaging at each visit. Escalate syncope, low pressure or rising BNP urgently.

💎

Start oxygen for low oxygen and diuretics for fluid overload while arranging targeted therapy. Treat sleep apnoea and iron deficiency in parallel.

📝

Example Usage & SOAP

CLINICAL SENTENCE

""38-year-old woman with scleroderma and effort breathlessness shows loud P2 with severe pulmonary hypertension.""

IN A SOAP NOTE

S: 42-year-old woman with effort breathlessness, fatigue and ankle swelling for months. O: BP 108/68, HR 96, RR 22, SpO2 92 percent on air, Temp 36.8C, raised neck veins, loud P2, right heave, clear lungs, mild oedema, echo high pressures with right strain. A: Severe pulmonary hypertension with right strain, likely Group 1. P: Urgent referral to hypertension centre, catheter workup, V/Q scan, oxygen and diuretic, pregnancy counsel, close follow-up.

DIFFERENTIAL DIAGNOSIS CONTEXT

Breathlessness with high echo pressures can be Group 2 from left failure, Group 3 from lung disease or Group 4 from old clots. Orthopnoea (flat breathlessness) with crackles favours left heart. Wheeze with smoking history favours lung cause. Mismatched scan defects favour chronic clot disease.

📊

Classifications & Scoring

GRADING SYSTEM

WHO Functional Class for Pulmonary Hypertension

Four-class symptom scale from no limits to rest symptoms grading severity and tracking response

STAGING SCALE

WHO Clinical Classification Groups 1 to 5

Five-group cause system splitting arterial, left heart, lung, clot and unclear causes to guide workup and therapy

SCORING TOOL

REVEAL Risk Score

Multivariable calculator using vitals, walk distance, blood markers and pressures to estimate survival and guide escalation

SCORING TOOL

ESC ERS Risk Stratification Tool

Three and four level tables using class, walk distance, markers and imaging to set low, intermediate and high risk

📈

Prognosis

SHORT-TERM OUTCOME

Short term risk follows right heart function, faint and low pressure. Stable low-risk disease often holds for months on therapy. Rest symptoms, large heart fluid and rising stress markers signal high risk. Acute illness, surgery or pregnancy can trigger rapid decline.

LONG-TERM PROGNOSIS

Long term course follows cause and therapy response. Drug responsive and surgically treated clot disease can hold well for years. Severe untreated arterial disease moves to right failure and shortens life. Left heart and lung forms track the base disease and right heart reserve.

📚

References & Coding

ICD-10 DIAGNOSTIC CODE

I27.20

LITERATURE CITATIONS & GUIDELINES

[1]ESC ERS Guidelines for pulmonary hypertension 2022

[2]WHO World Symposium classification of pulmonary hypertension

[3]NICE guidance on pulmonary hypertension management

MEDICAL DISCLAIMER — This content is intended for educational purposes and qualified healthcare professionals only. Always refer to current clinical diagnostic criteria, institutional protocols, and official guidelines. Medobo is not responsible for clinical decisions made based on this content.