Health condition · Clinically reviewed
Asthma, the guide that answers what to do next.
A treatable long-term condition — and modern UK care goes well beyond a blue inhaler. Here is how it is diagnosed, what MART actually means, and how to know when an attack needs 999.
Why trust this guide
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Clinically reviewed
Written by our editorial team and reviewed by a registered UK clinician before publication.
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Sourced from guidance
Checked against BTS/SIGN, NICE and peer-reviewed sources you can see at the end.
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Current for 2026
Reflects UK guidance on MART regimens, biologics for severe asthma, and inhaler-device choice.
Key facts
Asthma at a glance.
The essentials, in plain English — what it is, how common it is, how it is diagnosed, and how it is treated in the UK today.
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What it is
A chronic inflammatory airway condition causing reversible narrowing of the airways — wheeze, cough, chest tightness and breathlessness.
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How common
Around 5.4 million people in the UK — about 1 in 12 adults and 1 in 11 children.
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Diagnosis
Symptom pattern + objective testing — spirometry with bronchodilator reversibility, FeNO, or peak-flow variability.
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Modern preferred approach
MART — a combined inhaled steroid + long-acting reliever used both regularly and as needed.
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Severe asthma
Uncontrolled despite high-dose treatment — biologics like mepolizumab or benralizumab can transform care.
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Why control matters
Poor control increases risk of attacks, hospital admission and, in severe cases, death.
Why this guide matters
Modern asthma care has moved on.
Objective testing, MART regimens and biologics have changed what good asthma care looks like. The three points below shape everything else on this page.
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Objective tests decide the diagnosis
Symptoms alone can mislead. Spirometry, FeNO or peak-flow variability confirms asthma.
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MART changes control
A single ICS + formoterol inhaler used both regularly and as needed reduces attacks and simplifies life.
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Severe asthma has answers
Biologics transform care for uncontrolled severe asthma — specialist review is worth pushing for.
How the diagnosis is made
From first symptoms to a clear plan.
The steps a UK GP or asthma nurse will normally follow, in order — so you know what to expect and why.
Phase 1 · Recognising
Spotting the pattern and history
Phase 2 · Confirming
Spirometry, FeNO and trigger checks
Phase 3 · Managing
Start MART, review technique and control
- 01
Recognising
Pattern recognition
Wheeze, cough, chest tightness or breathlessness — variable, worse at night, or triggered by exercise, cold air, allergens or infection.
- 02
Recognising
History suggests it
Personal or family history of atopy, eczema or allergic rhinitis raises probability.
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Recognising
Objective tests are essential
Do not diagnose asthma on symptoms alone. Spirometry with reversibility is first-line where available.
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Confirming
FeNO or peak-flow variability
FeNO is a breath test of airway inflammation. Peak-flow diary over 2–4 weeks shows variability suggestive of asthma.
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Confirming
Consider trigger investigation
Allergen tests if seasonal or occupational triggers suspected. Occupational asthma has specific management.
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Managing
Start MART regimen
An inhaled corticosteroid + formoterol used both regularly and as reliever — improves control with fewer attacks.
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Managing
Review technique & control
Check inhaler technique and Asthma Control Test at 4–8 weeks. Step up only if control is genuinely inadequate.
Typical timeline: 2–8 weeks from first tests to a settled plan.
Symptoms
What asthma actually feels like.
Symptoms vary — day to day and week to week. Here is what to look for and when to act.
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Wheeze
A whistling sound breathing out, especially at night or with exertion.
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Persistent cough
Especially dry cough at night or in cold air — a common asthma presentation, particularly in children.
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Chest tightness
A pressure or heaviness across the chest — can be mistaken for cardiac symptoms.
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Breathlessness
Especially with exertion, cold air or infection — improves with a reliever inhaler.
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Waking at night
Symptoms waking you at night or first thing in the morning — a key marker of poor control.
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Trigger-related attacks
Pollen, pets, exercise, cold air, cigarette smoke, viral infection — each can trigger.
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Mucus and infection
Frequent chest infections that take longer than expected to clear — can suggest under-treated asthma.
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Signs of an attack
Reliever not lasting 4 hours, unable to speak in full sentences, blue lips, drowsiness — call 999.
Treatment
How asthma is treated in the UK.
Inhaled steroids first, MART regimens for most, biologics for severe disease — what each option does, and where it fits.
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Inhaled corticosteroid (ICS)
The foundation of asthma treatment — reduces airway inflammation and prevents attacks.
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MART regimen
ICS + formoterol as both regular preventer and reliever — simpler and more effective than separate inhalers for many.
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Short-acting bronchodilator
Salbutamol as reliever — if you need it more than three days a week, control needs review.
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Long-acting bronchodilator
Formoterol or salmeterol — added to ICS, not used alone.
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Leukotriene receptor antagonist
Montelukast — useful when allergic rhinitis coexists or exercise-induced symptoms are prominent.
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Biologic therapy
Mepolizumab, benralizumab, dupilumab and others for severe uncontrolled asthma in specialist care.
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Personalised asthma action plan
A written plan of what to take, when to step up, and when to seek help — reduces attacks and admissions.
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Address triggers
Stop smoking, treat allergic rhinitis, avoid known triggers where possible — all improve control.
What this guide is based on
The sources behind every claim on this page.
UK national guidance and specialist society standards, current at the time of last review.
Key references
Guidelines and standards we relied on.
A quiet reminder
This guide is for information, not medical advice.
Your GP or asthma nurse knows your history and can tell you which parts apply to you. If in doubt, ask for a review.
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BTS/SIGN/NICE. UK guideline on the management of asthma (2024 joint update).
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NICE. Asthma: diagnosis, monitoring and chronic asthma management (NG80).
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Asthma + Lung UK. Patient information and action plans.
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Royal College of Physicians. National Review of Asthma Deaths (NRAD).
Red flags
When asthma becomes an emergency.
Most asthma is well controlled with the right inhaler regimen. These are the situations where you should act today.
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Reliever not lasting 4 hours
Signals an attack — use your personalised action plan and seek urgent help.
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Cannot speak in full sentences
A sign of a severe attack — call 999.
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Blue lips or drowsiness
A life-threatening attack — call 999. Do not wait.
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Peak flow below 50% of best
Severe attack — follow your action plan and seek urgent help.
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Silent chest
No wheeze because air is barely moving — critical. Call 999.
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Frequent salbutamol use
Needing your reliever most days — control is inadequate. Book a review.
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Nocturnal symptoms
Waking at night with symptoms — poor control that responds well to review.
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Any attack in pregnancy
Under-treated asthma harms mother and baby — seek help early.
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Recent hospital admission
Anyone admitted with asthma needs follow-up within 2 working days — do not skip it.
Living with it
A long-term condition, but a very manageable one.
Four things that make the biggest difference day to day — technique, action plan, vaccination and regular reviews.
A quiet reminder
Good control is normal — settle for nothing less.
If you still wake at night, still need your reliever most days, or still miss school or work — treatment needs stepping up, not tolerating.
- 01 Technique
Get the inhaler right
Poor technique is the single biggest reason inhalers fail. Ask your pharmacist or nurse to check yours.
- 02 Action plan
A written plan changes outcomes
Personalised asthma action plans reduce attacks and admissions — free from Asthma+Lung UK.
- 03 Vaccines
Take the flu and COVID jabs
Both prevent attacks and complications — available on the NHS for anyone with asthma.
- 04 Reviews
Annual review as a minimum
Symptom score (ACT), inhaler technique and action plan reviewed each year, more often if unstable.
Frequently asked
Everything we get asked about asthma.
Quick answers on MART, inhaler technique, biologics, exercise, pregnancy and when to worry.
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How is asthma diagnosed?
By pattern of symptoms plus objective testing — spirometry with bronchodilator reversibility, a FeNO breath test, or peak-flow variability over 2–4 weeks. Symptoms alone are not enough.
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What is a MART regimen?
Maintenance And Reliever Therapy — a single inhaler (ICS + formoterol) used both regularly and as needed. It simplifies treatment and reduces attacks for many people.
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Should I still carry a blue reliever?
If you are on a MART regimen, no — your MART inhaler is your reliever too. If you are on separate preventer + salbutamol, yes.
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Do inhaled steroids cause weight gain?
No — the doses inhaled are far lower than oral steroids and act locally on the airways. Rinsing your mouth after use reduces oral thrush and hoarseness.
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What are biologics for asthma?
Injectable antibodies (mepolizumab, benralizumab, dupilumab, omalizumab) for severe asthma uncontrolled on high-dose inhalers — transformative for many people.
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Can I exercise with asthma?
Yes — and you should. Warm up thoroughly and use a reliever 15 minutes before if exercise triggers symptoms. Untreated exercise-induced asthma responds to a preventive step-up.
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What triggers should I avoid?
Cigarette smoke (including passive), untreated allergic rhinitis, house dust mites where relevant, pollen, cold air, and infections. Stopping smoking is transformative if you smoke.
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Is asthma more dangerous in pregnancy?
Under-treated asthma is — treated asthma is not. Continue your inhalers, get flu vaccination, and seek help early for any deterioration.
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What is a personalised asthma action plan?
A written plan — green/amber/red — telling you what to take routinely, what to do when symptoms worsen, and when to seek help. Free downloads via Asthma+Lung UK.
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When should I call 999?
Reliever not lasting 4 hours, cannot speak in full sentences, blue lips, drowsiness, or peak flow below 50% of best. Do not wait.