Relievers treat the symptom of asthma; preventers treat the disease itself. That single distinction explains most of modern asthma management — including why guidance has turned against reliever-only treatment, why people quietly stop their preventer, and why newer combined approaches like MART exist. If article-length asthma knowledge had to be compressed to one idea, this is it.
Two medicines for two different problems
Asthma is chronic inflammation of the airway lining, which makes airways swollen and hyper-reactive. On top of that inflammation, triggers cause acute bronchospasm — the airway muscles clamp down, producing the wheeze and tightness you feel.
- Relievers (short-acting bronchodilators like salbutamol — usually the blue inhaler) reverse the bronchospasm in minutes. They do nothing to the inflammation underneath
- Preventers (inhaled corticosteroids) reduce the inflammation over days to weeks, so triggers stop provoking spasms in the first place
Treating asthma with a reliever alone is treating fire alarms while ignoring the fire.
Why reliever-only treatment fell out of favour
For decades many people with "mild" asthma were managed on a blue inhaler alone. The evidence turned against this: the UK's National Review of Asthma Deaths found excessive reliever prescribing and inadequate preventer use were recurring features in fatal attacks — and, counterintuitively, many deaths occurred in people classed as mild. Current UK guidance (the joint BTS/NICE/SIGN guideline) has moved decisively toward anti-inflammatory treatment for essentially everyone with asthma, with reliever-only management no longer recommended. High reliever use is now treated as a risk marker in itself: needing salbutamol three or more times a week signals uncontrolled inflammation, and using multiple reliever canisters a year is associated with markedly higher attack risk.
Why preventer adherence fails — and how to beat it
Preventer inhalers are among the most commonly under-used effective medicines anywhere, for understandable reasons:
- No felt effect — a preventer dose does nothing you can sense, while a reliever rewards you instantly. Human behaviour follows the reward
- Feeling well — symptom-free weeks convince people they're "over it", so they stop, inflammation rebuilds, and symptoms return weeks later — rarely connected back to the stopped inhaler
- Steroid worry — the word alone deters people, although inhaled doses are tiny and lung-targeted
What works: anchor doses to an existing habit (toothbrushing is the classic), understand that feeling well is the medicine working, and treat rising blue-inhaler use as your early-warning light to re-establish the routine — not as a substitute for it.
Combination inhalers and MART
Modern treatment increasingly bundles the two jobs into one device. Combination inhalers pair an inhaled steroid with a long-acting bronchodilator. Under MART (maintenance and reliever therapy), one combination inhaler (containing formoterol, a fast-acting long-acting bronchodilator, plus steroid) serves as both daily preventer and as-needed reliever — so every time symptoms make you reach for relief, you're also treating the inflammation that caused them. Newer guidance also supports anti-inflammatory reliever (AIR) approaches in milder asthma, where a combined steroid-formoterol inhaler is used as-needed instead of a blue inhaler. If you're still on a classic blue-plus-brown setup and struggling, these are exactly the options an asthma review exists to discuss.
How to know your current setup is working
Well-controlled asthma looks like: reliever needed twice a week or less, no night waking from symptoms, no limitation on activity or exercise, and no attacks. Miss any of those tests and the answer is rarely "use more blue inhaler" — it's reviewing the preventer side: dose, technique (a large share of "treatment failure" is inhaler technique), adherence, or stepping up to a combination approach. Our guide to signs your asthma isn't well controlled covers the warning signals in detail.
Frequently asked questions
Can I just use my blue inhaler when I need it?
Current UK guidance says no — reliever-only treatment leaves airway inflammation untreated and is associated with higher attack risk. Almost everyone with asthma should be on anti-inflammatory treatment in some form.
What is MART in asthma?
Maintenance and reliever therapy: one combination inhaler (steroid + formoterol) used both daily and for symptom relief, so relief doses also treat inflammation. It replaces the separate blue inhaler for people on this plan.
I feel fine — can I stop my preventer?
Feeling fine is the preventer working. Stopping lets inflammation rebuild over weeks. Any step-down in treatment should be planned with your prescriber or asthma nurse, not decided by symptom-free streaks.
How quickly does a preventer start working?
Some improvement within days; full effect over several weeks of daily use. Keep the reliever available during that window.
References
- NICE/BTS/SIGN. Asthma: diagnosis, monitoring and chronic asthma management (NG245).
- Royal College of Physicians. Why asthma still kills: National Review of Asthma Deaths. 2014.
- Asthma + Lung UK. Preventer inhalers; MART. asthmaandlung.org.uk.
- Global Initiative for Asthma (GINA). Global strategy for asthma management and prevention.