Diagnosing Asthma
| Test | Finding in Asthma | Notes |
|---|---|---|
| Spirometry | FEV₁/FVC <70% (obstruction); reversibility >12% after bronchodilator | Confirm reversibility with salbutamol |
| Peak expiratory flow (PEF) | Variability >20% over 2 weeks | Home monitoring diary |
| FeNO (fractional exhaled nitric oxide) | ≥40 ppb suggests eosinophilic inflammation | Supports diagnosis; guides steroid response |
| Bronchial challenge test | PC20 <8 mg/mL (methacholine) | For borderline spirometry |
Inhaler Ladder (NICE / BTS Step-Up)
- Step 1: Short-acting beta-2 agonist (SABA) — salbutamol — for relief as needed
- Step 2: Add low-dose inhaled corticosteroid (ICS) — e.g. beclometasone — preventer inhaler
- Step 3: Add long-acting beta-2 agonist (LABA) — e.g. salmeterol / formoterol
- Step 4: Increase ICS dose; consider LTRA (montelukast) or long-acting muscarinic antagonist (LAMA)
- Step 5: Specialist biologics (dupilumab, mepolizumab for severe eosinophilic asthma)
Asthma Attack: When to Call 999Call emergency services if: SABA has no effect after 10 puffs, peak flow <33% predicted, silent chest (no wheeze despite distress), SpO₂ <92%, or confusion. These indicate life-threatening asthma.
Inhaler TechniqueUp to 80% of people use inhalers incorrectly. Poor technique is the most common cause of poor asthma control. A spacer significantly improves MDI delivery. Ask your nurse or pharmacist to check your technique.
What triggers asthma?
Common triggers: viral upper respiratory infections (most common), allergens (dust mite, pollen, pet dander), exercise, cold air, smoke/pollution, occupational chemicals (baker's asthma, isocyanates), emotions, NSAID use (aspirin-exacerbated asthma).
What is the difference between a preventer and reliever inhaler?
Preventer (ICS) — used daily to reduce airway inflammation and prevent attacks. Reliever (SABA) — used when symptomatic to quickly open airways. A reliever used more than twice a week suggests the preventer is inadequate.
Can asthma be cured?
No, but it can go into long-term remission — especially childhood asthma. About 50% of children with asthma have remission by adulthood, though it can return in later life.
What is MART therapy?
Maintenance and Reliever Therapy — a single inhaler (containing ICS + fast-acting LABA, e.g. budesonide/formoterol) used both as a daily preventer and as rescue medication. Evidence supports better control and fewer attacks.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.