Condition5 min read
Asthma
A chronic lung condition in which the airways become inflamed and narrow, causing cough, wheeze and shortness of breath. Most people control it well with inhalers, a written action plan and avoiding triggers.
Asthma affects all ages. Its symptoms include a persistent cough (especially at night), wheezing, shortness of breath and chest tightness, and symptoms worsen at night or with exertion. Management relies on reliever and preventer inhalers and an asthma action plan.
It is diagnosed by symptoms, listening to the chest, breathing tests and a home peak flow meter used for weeks. The NHS describes treatment pathways: an anti-inflammatory reliever inhaler, or a maintenance-and-reliever inhaler together (MART), or a preventer inhaler with a blue reliever, and for severe cases stronger medicines or biologic injections.
In one minute12
- What is it?
- A chronic lung disease in which the airways become inflamed and narrow.
- Who is usually affected?
- Affects all ages; the WHO estimates about 363 million people affected worldwide.
- Acute or chronic?
- Chronic; childhood asthma may ease with age, and in many people it lasts for life.
- Main symptoms
- Cough, especially at night, wheezing, shortness of breath, chest tightness.
- Red flags?
- Yes: a severe asthma attack that does not respond to the reliever inhaler.
- Preventable?
- Avoid triggers, smoking and air pollution, and follow a written action plan.
What is it?
Asthma is a chronic lung disease resulting from inflammation of the airways and tightening of the muscles around them, and it affects all ages.
The WHO estimates that about 363 million people have it worldwide (2023) and that about 442,000 deaths a year are attributed to it, with under-diagnosis and under-treatment in low-income countries.
Causes
The airways narrow, become inflamed and produce excess mucus on exposure to triggers.
Triggers: exertion, air pollution, cold air, allergens (pollen, dust, mould, animals), smoke and infection.
Risk factors
Family history, allergy (eczema, hay fever), urbanisation, premature birth or low birth weight, exposure to tobacco and pollution, obesity, and occupational irritants.
Symptoms
A persistent cough, especially at night, wheezing on breathing out or in, shortness of breath and chest tightness. Symptoms are often worse at night, in the early morning or with exertion.
How is it diagnosed?
Assessment of symptoms and listening to the chest, simple breathing tests, a portable peak flow meter (used at home for weeks), and blood tests may be requested.
Treatment
The treatment categories usually used are listed here; this is not a prescription. The doctor chooses the plan according to each person's condition; do not change any medicine or dose without a specialist.
Bronchodilators (reliever rescue inhalers), preventive inhaled steroids and combination inhalers, and using a spacer is preferred to make the inhaler more effective.
The NHS describes pathways: an anti-inflammatory reliever inhaler, or a maintenance-and-reliever inhaler together (MART), or a preventer inhaler with a blue reliever, and in severe cases stronger medicines, tablets or biologic injections. No doses are given.
Living with it
Learn your personal triggers, have a written asthma action plan, avoid tobacco smoke, and reduce air pollution. Most people affected live normally with correct inhaler use.
When do you need urgent help?
Call emergency services now 998
- An asthma attack: severe difficulty breathing, or the reliever inhaler does not help after the use set out in your plan, or the inhaler is not available. Call the ambulance and do not drive yourself.2
Get urgent care today
- A clear increase in coughing, wheezing or shortness of breath beyond the usual, or a repeated need for the reliever inhaler.2
See your doctor within days
Educational content only — no diagnosis, and no substitute for a clinician.
Common questions
Is asthma a lifelong disease?
The NHS describes it as a long-term condition, and childhood asthma may disappear in some people. Most people affected can control it with correct use of inhalers.2
Questions for your doctor
- What are my likely triggers and how do I avoid them?
- Do I have a written asthma action plan?
- Am I using my inhaler correctly, and do I need a spacer?
- When do I need urgent review?
- Do I need a breathing or allergy test?
References
- 1WHO. Asthma — Fact sheet. www.who.int/news-room/fact-sheets/detail/asthmaHealth agencies & guidelines · Accessed 2026-10-04
- 2NHS. Asthma. www.nhs.uk/conditions/asthma/Health agencies & guidelines · Accessed 2026-10-05
Review status: Edited content · Last updated:
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Educational content only — no diagnosis, and no substitute for a clinician.