Synopsis
Resolve chronic airway diagnostic uncertainty using objective evidence and treat demonstrated asthma and COPD traits without allowing an overlap label to replace careful clinical reasoning.
- Asthma and COPD can coexist, but 'overlap' has no single universally accepted diagnostic test and should not become a substitute for documenting each condition's evidence.
- Asthma is characterised by variable symptoms and variable expiratory airflow limitation; COPD requires persistent post-bronchodilator airflow obstruction in the right exposure and clinical context.
- A smoking history does not rule out asthma, and bronchodilator reversibility does not by itself rule out COPD; interpret magnitude, repetition, treatment and history together.
- When credible asthma features are present, ensure an inhaled corticosteroid-containing regimen and avoid LABA monotherapy or SABA-only asthma treatment.
- When COPD traits are present, address smoking, vaccination, pulmonary rehabilitation, breathlessness, exacerbations and long-acting bronchodilation rather than relying on inhaled corticosteroid alone.
- Blood eosinophils and FeNO can support an inflammatory trait but are affected by corticosteroids and do not determine diagnosis in isolation.
- Repeat quality-assured spirometry when the person is stable and treatment is documented; poor-quality or acute-illness spirometry creates false diagnostic certainty.
- Discordance between symptoms and spirometry should trigger alternatives such as heart failure, obesity, deconditioning, bronchiectasis, small-airways disease, ILO, anaemia or pulmonary vascular disease.
- Record the evidential basis and residual uncertainty in the notes so future clinicians know why ICS, bronchodilation or specialist testing was chosen.
- Review the diagnosis longitudinally: age, exposure, variability, attacks, imaging and response accumulate more reliable evidence than one clinic snapshot.
Key red flags
Previous life-threatening attack, repeated systemic corticosteroid, night waking, marked variability or escalating reliever use warrants an asthma-safe ICS-containing regimen while diagnostic refinement continues.
Clubbing, crackles, haemoptysis, inspiratory noise, orthopnoea, oedema, disproportionate hypoxaemia, systemic illness or restriction should move assessment beyond asthma and COPD rather than being forced into overlap.
Investigation priorities
Determine obstruction, persistence and immediate bronchodilator response.
Management branches
The record contains asthma, COPD, overlap or conflicting airway labels.
- Retrieve age at symptom onset, childhood or allergic history, attacks, smoking and occupational exposure, prior objective tests and response to treatment.
- Check whether each historical diagnosis was based on acceptable spirometry, documented variability or only symptoms and a therapeutic trial.
- Repeat quality-assured spirometry when stable, documenting bronchodilator and corticosteroid exposure, then add asthma tests using the current NICE sequence if needed.
- State separate conclusions: asthma evidence, COPD evidence, alternative disease evidence and what remains uncertain, rather than one unsupported overlap label.
Key medicines
Inhaled corticosteroid-formoterol AIR or MARTUse the exact licensed product, strength and as-needed or maintenance-and-reliever schedule selected under NICE and the local formulary.Confirm licence and maximum daily inhalations because products are not interchangeable. Review high use promptly; monitor candidiasis, dysphonia and systemic steroid exposure, and do not duplicate long-acting beta2 agonists.
Long-acting muscarinic antagonist add-onGive the locally formulary-approved inhaled once-daily or twice-daily product at its licensed device-specific adult dose after technique assessment.Dry mouth and urinary or ocular antimuscarinic effects can occur. Avoid powder or mist exposure to the eyes, assess glaucoma or urinary retention risk, and do not confuse maintenance LAMA with rapid rescue therapy.