Asthma
Reversible airway inflammation causing wheeze, cough and breathlessness.
Overview
Asthma is a chronic inflammatory airway disease with variable airflow obstruction. Most patients achieve good control with inhaled corticosteroids and trigger avoidance.
Symptoms
- • Wheeze
- • Cough, often nocturnal
- • Chest tightness
- • Breathlessness with triggers
Risk factors
- • Atopy (eczema, hay fever)
- • Family history
- • Allergen or smoke exposure
- • Viral respiratory infections in childhood
Causes
- • Allergic triggers
- • Exercise
- • Cold air
- • Viral infections
- • Occupational exposures
🚨 Red flags — seek urgent care
- • Unable to complete a sentence
- • Reliever inhaler not working
- • Peak flow <50% of best
- • Drowsiness, exhaustion, silent chest
When to seek care
- • Symptoms more than twice a week
- • Night-time waking
- • Reliever needed more than twice a week
Diagnosis
- • History of variable wheeze, cough, chest tightness, breathlessness (often nocturnal or with triggers)
- • Objective tests: FeNO ≥40 ppb, spirometry with reversibility (FEV1 increase ≥12% post-bronchodilator), peak-flow variability ≥20%
- • Bronchial challenge testing where diagnosis remains uncertain
Treatment
- • MART regimen preferred: low-dose ICS-formoterol as both maintenance and reliever
- • Step up: low → moderate → high-dose ICS-formoterol; add LTRA, LAMA
- • Severe asthma: biologics (omalizumab, mepolizumab, benralizumab, dupilumab) based on phenotype
- • Personalised asthma action plan, inhaler technique review, trigger avoidance
- • Treat acute attacks with high-dose SABA via spacer, oral steroids, oxygen if SpO2 <94%
Prevention
- • Avoid known triggers (allergens, smoke, NSAIDs if sensitive)
- • Annual influenza and pneumococcal vaccination
- • Smoking cessation and avoid second-hand smoke
- • Maintain controller medication adherence
Complications
- • Life-threatening or near-fatal asthma attack
- • Airway remodelling and fixed airflow obstruction
- • Side effects of high-dose steroids
- • Reduced quality of life, school/work absence
Education & self-care
A written asthma action plan, correct inhaler technique, and an annual review reduce attacks. Smoking and second-hand smoke must be avoided.
Frequently asked questions
Is asthma lifelong?
Often, though children may grow out of symptoms. Adults usually need long-term controller therapy.
Do I always need a steroid inhaler?
For anything beyond very mild intermittent asthma — yes. It treats the underlying inflammation, not just symptoms.
Why do I need a preventer if I feel fine?
Asthma is driven by underlying airway inflammation that is present even when you feel well. Daily inhaled corticosteroids reduce attacks, hospital admissions and asthma deaths — relievers alone do not.
What is a personal asthma action plan?
A one-page plan that tells you what to do when symptoms are good, getting worse, or in an attack. People who have one are four times less likely to be admitted to hospital.
Can I exercise with asthma?
Yes — exercise is encouraged. If activity triggers symptoms, your reliever inhaler can be used 15 minutes before; persistent exercise-induced symptoms usually mean preventer treatment needs stepping up.