Breathlessness Algorithm

1

Safety

Red Flags — Exclude Life-Threatening Causes Immediately

Done

Assess these FIRST before any structured history. If present, act immediately — do not complete the algorithm.

SpO₂ < 92% on air Cyanosis, unable to complete sentences, accessory muscle use → 999

Haemodynamic compromise HR >130, BP <90 systolic, mottled peripheries, altered consciousness → 999

Suspected PE Pleuritic chest pain + tachycardia + unilateral leg swelling + DVT risk factors → 999 (CTPA same day if stable)

Tension pneumothorax Sudden onset, tracheal deviation, absent breath sounds, hypotension → 999

Acute severe asthma PEFR <33%, silent chest, cyanosis, exhaustion, bradycardia → 999

Acute pulmonary oedema Orthopnoea, pink frothy sputum, bilateral crackles, elevated JVP → 999

Anaphylaxis Acute onset dyspnoea + urticaria/angioedema/hypotension after trigger → 999 + IM adrenaline 0.5 mg

Stridor / upper airway Inspiratory noise, drooling, unable to swallow, epiglottitis features → 999

Haemoptysis + weight loss Frank blood, >4 weeks, smoker / asbestos exposure → 2WW lung (NICE NG12)

New unilateral wheeze + SVC syndrome Facial plethora, arm swelling, headache → Same-day haematology / oncology

Breathlessness is the third most common presentation in UK general practice and carries a broad differential from trivial to immediately life-threatening. PE causes 25,000 deaths/year in the UK; missed acute asthma kills around 1,400/year. SpO₂ below 92% mandates urgent assessment as compensatory mechanisms are near-exhausted. Haemoptysis with weight loss in a smoker meets NICE NG12 criteria for 2WW lung cancer referral; the positive predictive value is >3% — the referral threshold.

2

Diagnose

Confirm Onset, Pattern & Severity — Structured History

Done

Use SOCRATES + targeted questions to narrow the differential. One key question separates most diagnoses.

Onset & speed

Sudden (<minutes) → PE, pneumothorax, anaphylaxis, acute pulmonary oedema
Hours–days → Pneumonia, asthma exacerbation, acute HF
Weeks–months → COPD, malignancy, anaemia, pleural effusion, anxiety

Triggering factors

Exercise → cardiac / COPD / deconditioning · Rest → severe cardiorespiratory disease · Allergen → asthma / anaphylaxis · Position (flat) → HF, phrenic palsy · Night symptoms → asthma

Associated symptoms

Wheeze → asthma / COPD · Pleuritic pain → PE / pneumonia / pleurisy · Ankle swelling + orthopnoea → HF · Productive cough → infection · Haemoptysis → PE / TB / malignancy · Palpitations → arrhythmia · Stridor → upper airway

Functional severity

Use MRC Dyspnoea Scale: Grade 1 (strenuous exercise only) to Grade 5 (too breathless to leave home). Document baseline vs change.

Background history

Smoking (pack-years) · Prior asthma / COPD / HF / PE / malignancy · Recent immobility / long-haul flight / surgery (DVT/PE risk) · Medications (β-blockers worsen asthma; ACEi cause cough)

DVT/PE risk

Apply Wells PE score if PE suspected: ≤4 = low risk → D-dimer; >4 = high risk → CTPA directly. Do not apply Wells if already sending to 999.

Occupational / environmental

Asbestos (mesothelioma) · Farming / birds (extrinsic allergic alveolitis) · Silica (silicosis) · Always ask about pets and hobbies

The MRC Dyspnoea Scale is validated, reproducible, and tracks treatment response over time — document grade at every consultation. Speed of onset alone correctly identifies the probable mechanism in ~70% of presentations. Wells score is a validated clinical decision rule that stratifies pre-test probability for PE; using it reduces unnecessary CTPA by 40% without missing significant PE (NICE CG144). Occupational history is frequently omitted and can reveal treatable, compensable diagnoses.

3

Diagnose

Classify the Working Diagnosis — Phenotyping by Pattern

Done

Classify by acuity and mechanism. Treatment diverges sharply between these groups.

Obstructive airway
(Asthma / COPD)

Variable wheeze · Diurnal variation · Atopy / smoking history · Reversibility on spirometry (FEV₁/FVC <0.7 in COPD). Spirometry is diagnostic gold standard — not peak flow alone.

Cardiac dyspnoea
(HF / arrhythmia)

Orthopnoea, PND, ankle oedema, elevated JVP, S3 gallop. BNP / NT-proBNP — if normal, heart failure unlikely. Echo for EF and structural disease.

Thromboembolic
(PE / DVT)

Wells score. D-dimer only if Wells ≤4 and age-adjusted threshold (age × 10 µg/L if >50). Wells >4 → direct to CTPA.

Infective / inflammatory
(Pneumonia / pleuritis)

Fever, productive cough, crackles, consolidation on CXR. Use CRB-65 in community: score ≥2 → hospital admission.

Pleural disease
(Effusion / pneumothorax)

Reduced breath sounds, stony dull (effusion) or hyper-resonant (pneumothorax). CXR first-line. Exudate vs transudate → Light's criteria at aspiration.

Haematological
(Anaemia / metHb)

Pallor, tachycardia, fatigue, exertional dyspnoea disproportionate to exam. FBC + haematinics. SpO₂ unreliable in methaemoglobinaemia — co-oximetry needed.

Psychogenic / deconditioning

Diagnosis of exclusion. Breathing pattern disorder features: sighing, hyperventilation, tingling, inconsistency. Consider Nijmegen questionnaire. Do not diagnose anxiety until all organic causes excluded.

Classifying the mechanism determines the entire management pathway. Treating presumed asthma with bronchodilators in undiagnosed HF delays definitive care and may cause harm. BNP has a high negative predictive value (>95%); a normal BNP effectively excludes significant HF and avoids unnecessary echocardiography. CRB-65 is validated for community-acquired pneumonia severity and admission decisions (NICE NG138). Psychogenic breathlessness is common (10–20% of presentations) but cannot be diagnosed until organic causes are excluded — never anchor on this diagnosis prematurely.

4

Diagnose

Targeted Examination — Focused Clinical Assessment

Done

Examine in order of urgency. Each finding should confirm or refute your working hypothesis.

Vital signs first

RR >25 = severe respiratory compromise → act now. SpO₂ on pulse oximetry (mandatory). HR, BP, temperature. Calculate NEWS2 score — score ≥5 → consider hospital admission.

General inspection

Position (sitting forward → severe obstruction) · Pursed-lip breathing → COPD · Accessory muscle use · Cyanosis (central vs peripheral) · Cachexia → malignancy · Clubbing → fibrosis, malignancy, bronchiectasis

Respiratory

Expansion (symmetry → pneumothorax if asymmetric) · Percussion (dull → effusion / consolidation; hyperresonant → pneumothorax) · Auscultation: wheeze (expiratory = obstruction), crackles (fine = fibrosis / HF, coarse = infection), bronchial breathing (consolidation), absent sounds (effusion / pneumothorax)

Cardiovascular

JVP elevation → HF / SVCO / COPD cor pulmonale · Apex beat position · Heave (RV overload) · Heart sounds: S3 gallop (HF), loud P2 (pulmonary hypertension) · Peripheral oedema (bilateral → HF; unilateral → DVT)

Peak flow (if asthma suspected)

Compare to predicted and personal best. <50% personal best = acute severe. <33% = life-threatening. Do NOT perform if SpO₂ <92% or patient too distressed.

Legs

Unilateral calf swelling, redness, tenderness → DVT → elevates PE pre-test probability. Bilateral pitting oedema → cardiac / hypoalbuminaemia / venous insufficiency.

ENT / upper airway

Inspiratory stridor → laryngeal or tracheal obstruction. Uvular deviation → peritonsillar abscess / epiglottitis. Do NOT examine throat if epiglottitis suspected (risk of complete obstruction).

NEWS2 is the NHS-mandated early warning score for acute deterioration; a score ≥5 should trigger senior review or hospital transfer discussion. SpO₂ monitoring changes management in 30% of breathless presentations. Percussion is underutilised in primary care but has 85% sensitivity for moderate-large pleural effusion. Clubbing should always prompt investigation as it is associated with significant underlying disease (malignancy, ILD, bronchiectasis) in >80% of cases.

5

Diagnose

Investigations — Targeted Testing to Confirm Diagnosis

Done

Investigate based on working diagnosis. Avoid blanket requesting — every test should answer a specific question.

First-line all presentations

CXR — consolidation, cardiomegaly, pleural effusion, hyperinflation, mass · SpO₂ (point-of-care) · ECG — AF, RV strain (SI QIII TIII in PE), LVH, ischaemia

Suspected HF

NT-proBNP: <125 pg/mL = HF unlikely; 125–400 = possible → Echo within 3 months; >400 = probable → Echo within 6 weeks (NICE NG106). Add U&Es, eGFR, LFTs, TFTs, FBC

Suspected asthma

FeNO ≥40 ppb = eosinophilic airway inflammation (supports asthma) · Spirometry + bronchodilator reversibility (>12% AND >200 mL improvement = positive) · Bronchial challenge if equivocal · Peak flow diary (2-week record)

Suspected COPD

Post-bronchodilator spirometry (FEV₁/FVC <0.7 confirms) · FBC (polycythaemia), α₁-antitrypsin (if early onset / minimal smoking)

Suspected PE

Wells ≤4: D-dimer (age-adjusted). If elevated → CTPA. Wells >4: direct CTPA (do NOT do D-dimer). If CTPA unavailable urgently → anticoagulate empirically pending imaging.

Suspected pneumonia

CXR · CRP (guides antibiotic decision with CRB-65) · If admitted: urine pneumococcal antigen, blood cultures, legionella antigen

Suspected malignancy

CXR (mass, collapse, effusion, pleural thickening) · CT chest via 2WW pathway · FBC, LFTs, calcium, albumin

Suspected anaemia

FBC + film · Ferritin, B12, folate · Reticulocyte count if haemolysis suspected · Haematinics only useful if FBC abnormal

Do NOT investigate

D-dimer if Wells >4 (false negatives; go direct to CTPA) · Spirometry during acute exacerbation (inaccurate) · Routine ECHO without clinical/BNP indication (low yield, long wait)

NT-proBNP has a negative predictive value of 98% for HF — it is the single most efficient test for ruling out cardiac dyspnoea in primary care. FeNO is now recommended by NICE (NG80) as part of asthma diagnosis; a value ≥40 ppb has a positive likelihood ratio of ~15 for eosinophilic asthma. Age-adjusted D-dimer (age × 10 µg/L for patients >50) increases specificity without sacrificing sensitivity, avoiding unnecessary CTPA in older patients. CXR is normal in ~25% of PEs and should not be used to exclude it.

6

Refer

Referral Criteria — When to Escalate & to Whom

Done

Match urgency to clinical risk. When in doubt, refer more urgently, not less.

999 Emergency

SpO₂ <92% · NEWS2 ≥7 · Haemodynamic instability · Suspected tension pneumothorax · Anaphylaxis · Suspected acute STEMI with dyspnoea · Silent chest in asthma

Same-day hospital

SpO₂ 92–94% with dyspnoea at rest · Suspected PE (Wells >4) · Acute severe asthma PEFR <50% not responding to nebulisers · Community pneumonia CRB-65 ≥2 · Spontaneous pneumothorax (primary >2 cm on CXR) · Suspected cardiac tamponade · Acute HF with SpO₂ <94%

2WW Lung Cancer
NICE NG12

Age ≥40 + haemoptysis (any) · Age ≥40 + ≥2 of: cough, fatigue, SOB, chest pain, weight loss, appetite loss · CXR suspicious for malignancy · Persistent unexplained hoarseness + CXR normal → fast-track laryngoscopy

Urgent respiratory
(Within 2 weeks)

New pleural effusion (undiagnosed) · Suspected ILD (bilateral crackles, clubbing, CXR changes) · Haemoptysis without 2WW criteria but >3 episodes · Suspected malignant pleural mesothelioma (asbestos exposure)

Routine respiratory

Confirmed COPD requiring specialist spirometry · Difficult / uncontrolled asthma despite step 3 treatment · Bronchiectasis (confirmed or suspected) · Suspected pulmonary hypertension (echo referral)

Urgent cardiology

New HF (BNP elevated) → Echo within 6 weeks (NICE NG106) · New AF with dyspnoea → assess for cardioversion · Decompensated chronic HF not responding to diuretics

Manage in primary care

Mild COPD (GOLD 1–2) with good symptom control · Well-controlled asthma (step 1–2) · Deconditioning / obesity-related dyspnoea · Anxiety / breathing pattern disorder (after exclusion) · Mild anaemia with identified cause

The 2WW lung pathway detects lung cancer at an earlier stage and improves 5-year survival; 1 in 10 appropriate 2WW referrals will have lung cancer. BNP-guided referral for echocardiography is the NICE NG106 recommended pathway — it is cost-effective and reduces unnecessary echocardiography. New undiagnosed pleural effusions require urgent respiratory referral as 30–40% have an underlying malignant aetiology. Spontaneous pneumothorax >2 cm requires same-day review as conservative management risks tension progression.

7

Treat

Treatment Pathway — Condition-Specific Management

Done

First-line treatment depends on confirmed diagnosis. Each pathway below follows UK NICE/BTS/GOLD guidance.

First-line initial therapy by diagnosis

Asthma (newly diagnosed)

ICS low dose Step 1

Beclometasone dipropionate 200 mcg BD MDI (or equivalent) + SABA PRN (salbutamol 100 mcg 1–2 puffs). Check inhaler technique at every visit.

COPD (newly diagnosed)

SAMA or LAMA Step 1

Tiotropium 18 mcg OD (HandiHaler) OR Umeclidinium 55 mcg OD. SABA PRN (salbutamol 100 mcg) for rescue. Add ICS only if FEV₁ <50% + ≥2 exacerbations/year.

Heart failure (new, stable)

ACEi + β-blocker 1st line

Ramipril 2.5 mg OD (titrate to 10 mg) + bisoprolol 1.25 mg OD (titrate to 10 mg). Add loop diuretic (furosemide 40 mg OD) if fluid overloaded. REFER for echo concurrently.

Community pneumonia (CRB-65 0–1)

Amoxicillin 500 mg TDS 5 days

If penicillin allergic: doxycycline 200 mg then 100 mg OD for 5 days. Atypical cover: add clarithromycin 500 mg BD if atypical features (dry cough, bilateral infiltrates).

PE (confirmed, stable)

DOAC Anticoagulant

Apixaban 10 mg BD for 7 days then 5 mg BD (NICE preferred). Or rivaroxaban 15 mg BD for 21 days then 20 mg OD. Duration: provoked = 3 months; unprovoked = 6 months, specialist review.

Iron deficiency anaemia

Ferrous sulfate 1st line

200 mg OD (one tablet OD, on alternate days if tolerated). Recheck FBC and ferritin at 4 weeks. Treat for 3 months after Hb normalised to replenish stores. Investigate cause simultaneously.

Asthma escalation ladder (BTS/SIGN 2023)

Step 1ICS low dose + SABA PRN — Beclometasone 200 mcg BD. Counsel on daily ICS even when asymptomatic. Check inhaler technique.

Step 2ICS low dose + LABA — Add formoterol or salmeterol (via combination inhaler e.g. Fostair 100/6, 1 puff BD). Do not use LABA without ICS — FATAL RISK.

Step 3ICS medium dose + LABA — Increase beclometasone to 400 mcg BD equivalent. Trial of LTRA (montelukast 10 mg OD) as add-on. Review in 4 weeks.

Step 4Specialist review — Refer to respiratory. Options: high-dose ICS, theophylline, oral prednisolone, biologic therapy (mepolizumab, dupilumab). Confirm adherence and technique first.

COPD escalation ladder (NICE NG115 / GOLD 2024)

Step 1LAMA monotherapy — Tiotropium 18 mcg OD or umeclidinium 55 mcg OD. Superior to LABA monotherapy for breathlessness and exacerbation reduction.

Step 2LAMA + LABA (dual bronchodilation) — e.g. Umeclidinium/vilanterol (Anoro Ellipta) OD. Use when symptoms persist on LAMA alone. MRC ≥3.

Step 3Triple therapy: LAMA + LABA + ICS — e.g. Trelegy Ellipta (fluticasone/umeclidinium/vilanterol) OD. Reserve for: ≥2 exacerbations/year AND FEV₁ <50% AND blood eos ≥300 cells/µL.

Step 4Specialist review — Consider theophylline (monitor levels), azithromycin prophylaxis (for frequent exacerbators, check QTc, NTM), roflumilast, long-term oxygen therapy (LTOT) assessment.

⚠ Acute exacerbation management (COPD / Asthma in primary care):
Salbutamol 2.5 mg nebulised (or 4–10 puffs via spacer) · Ipratropium 500 mcg nebulised · Prednisolone 40 mg OD for 5 days · Antibiotics if purulent sputum (amoxicillin 500 mg TDS or doxycycline 200/100 mg) · Reassess SpO₂ after 15 minutes. Target SpO₂ 88–92% in COPD (not 94–98%).

ICS in asthma reduces exacerbations by 55% and asthma deaths by 70% — it is the most important treatment in asthma management (BTS/SIGN 2023). LAMA monotherapy in COPD reduces exacerbations by 17% vs LABA and by 52% vs SABA alone. Triple therapy in COPD reduces exacerbations by 25% vs dual bronchodilation but increases pneumonia risk by 53% — reserve for appropriate phenotype (frequent exacerbators with high eosinophils). DOACs are preferred over LMWH/warfarin for PE in most patients; apixaban has the most favourable safety profile with lowest bleeding risk (NICE TA341). Target SpO₂ 88–92% in COPD patients receiving supplemental oxygen — hypercapnic drive in CO₂ retainers means high-flow oxygen risks respiratory depression.

8

Lifestyle

Non-Pharmacological Interventions — Essential Adjuncts

Done

Lifestyle modifications are treatments, not optional extras. Prescribe them with the same specificity as drugs.

Smoking cessation Single most impactful intervention for COPD, asthma, lung cancer, and cardiovascular disease. Refer to NHS Stop Smoking Service. NRT + varenicline combination doubles quit rates vs NRT alone. Every consultation is an opportunity — brief intervention takes 30 seconds.

Pulmonary rehabilitation (PR) 6–8 week supervised exercise programme. Recommended for all COPD patients with MRC ≥3. Reduces hospital admissions by 40%, improves exercise capacity and QoL. Refer via respiratory or self-referral (NHS England PR programme).

Vaccinations Annual influenza vaccine (all respiratory / cardiac patients) · Pneumococcal (PPV23 once; PCV13 if immunocompromised) · COVID-19 boosters per seasonal programme · RSV vaccine if eligible (age ≥75 from 2024/25 programme).

Weight management Obesity (BMI >30) independently worsens dyspnoea via reduced chest wall compliance and increased O₂ demand. Even 5–10% weight loss significantly improves breathlessness, exercise tolerance, and CPAP compliance in OSA. Refer to NHS Tier 2/3 weight management services if BMI >35.

Breathing retraining Diaphragmatic breathing, pursed-lip breathing (COPD) · Buteyko technique (asthma, evidence-supported for symptom management) · Physiotherapy-led breathing pattern disorder programme for hyperventilation syndrome. Nijmegen score >23 = refer to respiratory physiotherapy.

Exercise and physical activity Deconditioning is reversible. Prescribe structured exercise: 150 minutes moderate-intensity/week (NICE PH44). Cardiac rehab for HF patients. Even 10 minutes/day walking improves functional capacity in COPD. Social prescribing to community walking groups / BHF programmes.

Allergen avoidance (asthma) House dust mite reduction: mattress covers, wash bedding ≥60°C weekly, dehumidify. Avoid known triggers (NSAIDs in NSAID-sensitive asthma, β-blockers, occupational exposures). Pet dander: difficult to eliminate — HEPA filters reduce but do not abolish exposure.

Home environment COPD and asthma: damp, mould, wood-burning stoves, and gas cooking significantly worsen symptoms. Refer to housing officer if poor housing contributes. Advise air purifier. Indoor air pollution is increasingly recognised — WHO PM2.5 thresholds relevant.

Mental health support Anxiety and depression affect 40% of COPD and 20% of HF patients — breathlessness generates fear, which worsens breathlessness (hyperventilation cycle). Offer Talking Therapies (IAPT) referral. CBT has evidence for both asthma and COPD self-management.

Advance care planning (COPD / HF) For MRC Grade 4–5 or advanced HF: sensitive ACP discussion about resuscitation preferences, preferred place of care, and goals. Refer to palliative care for breathlessness management (opioids, fan therapy, anxiolytics).

Pulmonary rehabilitation is one of the most cost-effective interventions in all of medicine — NICE analysis shows it costs ~£2,000 per QALY gained in COPD, far below the £20,000–30,000 threshold. Smoking cessation slows FEV₁ decline in COPD from ~50 mL/year to near-normal ~25 mL/year — no pharmacological intervention comes close. Influenza vaccination in COPD reduces exacerbations by 30% and hospitalisation by 50% (Cochrane review). The breathlessness-anxiety cycle is a key driver of functional impairment; treating only the physiological component without addressing the psychological response leads to persistent disability. Prescribe rehabilitation as you would a drug — with dose, frequency, and duration.

9

Safety

Follow-Up, Monitoring & Safety-Netting

Done

Every breathless patient needs a clear follow-up plan and explicit safety-netting before leaving. Document both in the records.

Acute presentation
(Infection / exacerbation)

48–72 hours: Phone or in-person review if not improving or worsening. Confirm treatment response. If still febrile / SpO₂ declining → same-day hospital assessment. Re-examine and re-score NEWS2.

New diagnosis
(Asthma / COPD / HF)

2 weeks: Confirm diagnosis, review investigation results (spirometry, BNP, echo request). Assess inhaler technique. Check adherence and tolerability of new medications. Smoking cessation referral confirmed?

Medication titration

4 weeks: U&Es / eGFR / potassium after starting ACEi or ARNi in HF. FBC + ferritin after 4 weeks iron therapy. BP + renal function if starting diuretics. Theophylline level (target 10–20 mg/L) at steady state (3–5 days).

Stable chronic disease
(COPD / Asthma / HF)

3 months: Annual structured review minimum. COPD: CAT score, exacerbation frequency, smoking status, inhaler technique, PR attendance, vaccinations, spirometry. Asthma: PAAP in place, symptom control (ACQ/RCP 3 questions), PEFR. HF: weight, fluid status, BNP trend, LVEF on echo.

Anticoagulation for PE

3 months: Review duration of anticoagulation. Provoked PE (immobility, surgery) → stop at 3 months. Unprovoked → discuss extended treatment (reduced-dose apixaban 2.5 mg BD). Thrombophilia screen if <45 years or recurrent. Cancer-associated PE → LMWH or DOAC, oncology input.

Post-referral monitoring

Confirm 2WW referral acknowledged within 2 working days. Chase echo result if not received within 6 weeks (HF pathway). Ensure patient has specialist contact if condition deteriorates before appointment.

Safety-net: Call 999

Sudden severe worsening of breathlessness at rest · SpO₂ drops below 92% · Cannot complete a sentence · Cyanosis · Collapse or altered consciousness · Chest pain with breathlessness (possible ACS / PE) · Stridor develops

Safety-net: Same-day GP

Breathlessness not improving after 48 hours of treatment · Fever returning after initial improvement (secondary infection / empyema) · Increasing wheeze not responding to reliever · New ankle swelling · Haemoptysis develops · Cough productive of green / brown sputum after 5 days

Personalised action plan

All asthma patients must leave with a written Personalised Asthma Action Plan (PAAP) — reduces admissions by 40% (Cochrane). COPD patients: self-management plan with rescue antibiotic + prednisolone prescription for exacerbations (discuss with patient, document agreement).

Safety-netting is a medicolegally critical part of any breathlessness consultation and should be documented verbatim in the patient record. Written safety-netting instructions improve patient recall by 60% vs verbal-only advice. Renal function monitoring after ACEi initiation in HF detects acute kidney injury (occurs in 10–20%); this is a key prescribing safety competency assessed in the RCGP SCA. Personalised asthma action plans are the most evidence-based intervention for reducing asthma mortality; only 30% of UK asthma patients have one (NAP5 audit). The 48-hour safety-net is particularly important in pneumonia: failure to improve by 48 hours suggests resistant organism, complication (empyema, abscess), or missed diagnosis. Good safety-netting is not optional — it is the standard of care.