Asthma UK: Symptoms, Triggers, Inhalers & Treatment

Asthma is one of the most common chronic conditions in the UK, affecting 1 in 11 children and 1 in 12 adults. The majority of asthma deaths — around 1,400 per year in the UK — are considered preventable with better management. This condition guide covers the full clinical picture: what asthma is, how it affects the airways, how it is diagnosed, the complete NICE NG245 stepwise treatment approach, how inhalers work, and how to manage your asthma effectively. Use the guide links below to explore specific topics in depth.

What Is Asthma?

Asthma is a chronic condition in which the airways are persistently inflamed and hypersensitive to certain stimuli. When exposed to a trigger, three things happen simultaneously in the airways:

1. Inflammation — the airway lining becomes more swollen and produces excess mucus
2. Bronchoconstriction — smooth muscle surrounding the airways contracts, narrowing the lumen
3. Hyperresponsiveness — already-sensitised airways overreact to stimuli that would not affect a person without asthma

The result is a narrowed, partially obstructed airway that makes breathing — particularly exhaling — effortful. Between episodes, most people with well-controlled asthma have near-normal airway function.

For a full clinical overview, see: Asthma Explained: Symptoms, Triggers, Causes & Treatment.

Types of Asthma

Allergic (Atopic) Asthma

The most common form — particularly in children and young adults. Triggered primarily by allergens (pollen, house dust mites, animal dander, mould). Often associated with eczema and hay fever. IgE-mediated immune response is the underlying mechanism.

Non-Allergic Asthma

Not driven by allergen exposure. More common in adults, particularly women. Triggers include respiratory infections, cold air, exercise, air pollution, and irritants. Often more difficult to control than allergic asthma.

Occupational Asthma

Caused or significantly worsened by workplace exposures — particularly in bakers, hairdressers, painters, laboratory workers, and those working with animals or isocyanates. Early recognition and avoidance of the causative agent is critical; continued exposure causes progressive, potentially irreversible airway damage.

Exercise-Induced Bronchoconstriction (EIB)

Airway narrowing during or after exercise, typically peaking 5–10 minutes after stopping. Common in people with underlying asthma but can occur in isolation. Pre-treatment with a reliever inhaler 15–30 minutes before exercise is the standard approach.

Severe (Refractory) Asthma

Asthma that remains poorly controlled despite optimal technique, adherence, and high-dose ICS+LABA therapy. Affects approximately 5–10% of people with asthma. May require biologic therapies or oral corticosteroids under NICE NG245 Steps 4–5. See: Asthma Treatment Types: Part 2 — Advanced and Combination Therapies.

Symptoms of Asthma

Asthma symptoms are typically variable (changing over time), reversible (improving with treatment), and often worse at night or in the early morning. The four cardinal symptoms are:

• Wheezing — a high-pitched whistling sound when breathing, particularly on exhaling
• Breathlessness — difficulty breathing, particularly during or after activity or at night
• Chest tightness — a feeling of pressure, heaviness, or constriction in the chest
• Coughing — often worse at night; may be the only symptom in cough-variant asthma

Not everyone has all four symptoms. Some people present with chronic cough alone. Symptoms may be absent between episodes, which can make diagnosis challenging. Seek medical advice for any unexplained recurrent breathlessness, wheeze, or persistent cough.

Common Asthma Triggers

Triggers vary significantly between individuals. Identifying your personal triggers is an important part of asthma self-management.

For seasonal trigger guidance, see: Autumn Asthma: Why Your Asthma Gets Worse in Autumn — and How to Manage It.

How Asthma Is Diagnosed

Asthma diagnosis follows NICE NG245 guidance and typically involves:

1. Symptom history — pattern of wheeze, breathlessness, chest tightness, and cough; triggers; variability over time and with treatment
2. Spirometry — measures FEV1 and FVC. An obstructive pattern (FEV1/FVC <0.7) supports asthma
3. Bronchodilator reversibility — spirometry repeated after salbutamol. A ≥12% and ≥200ml improvement in FEV1 is a positive result
4. FeNO testing — elevated fractional exhaled nitric oxide (>40 ppb) indicates eosinophilic airway inflammation and supports allergic asthma diagnosis; recommended by NICE for adults
5. Peak flow variability — recording PEF morning and evening for 2–4 weeks; variability >20% supports asthma

Asthma Treatment: NICE NG245 Stepwise Approach

NICE NG245 (2024) recommends a stepwise approach — starting with the lowest effective therapy and stepping up when control is inadequate. The goal is full asthma control using the minimum effective medication.

For detailed explanations of each step, see: Types of Asthma Treatment Explained: From Blue Inhalers to Long-Term Control and Asthma Treatment Types: Part 2 — Advanced and Combination Therapies.

Inhaler Types Explained

Reliever Inhalers (SABA)

The blue inhaler most people associate with asthma. Salbutamol (Ventolin, Salamol) stimulates beta-2 receptors in airway smooth muscle, causing rapid relaxation and bronchodilation within 2–5 minutes. Duration approximately 4–6 hours. SABAs are for symptom relief only — they do not treat underlying inflammation. Using a reliever more than twice weekly indicates inadequate control and a preventer should be started or reviewed.

Preventer Inhalers (ICS)

Typically brown, red, orange, or purple. Contain an inhaled corticosteroid that reduces airway inflammation when taken every day. Effect is cumulative — full benefit takes 1–2 weeks to establish. Must be taken regularly even when feeling well. Rinsing the mouth after use reduces the risk of oral thrush.

Combination Inhalers (ICS + LABA)

Contain both an ICS and a long-acting beta-2 agonist (LABA) in one device. Examples: Seretide (fluticasone + salmeterol), Fostair (beclometasone + formoterol), Symbicort (budesonide + formoterol). LABAs bronchodilate for 12+ hours but must always be used alongside an ICS and must not be used as reliever-only therapy.

Device Types: pMDI vs DPI

Pressurised metered-dose inhalers (pMDI) require slow, coordinated inhalation. Dry powder inhalers (DPI) require a fast, forceful breath. Incorrect technique dramatically reduces drug delivery — studies show up to 90% of users make at least one critical error. For step-by-step technique guidance, see: How to Use an Asthma Inhaler Correctly: A Step-by-Step Guide.

For a complete overview of all inhaler types, see: Asthma Inhalers: Your Complete Guide to Relievers, Preventers and Combination Inhalers.

Ventolin (Salbutamol) — The Blue Reliever Inhaler

Ventolin Evohaler (salbutamol 100mcg per actuation, 200 doses) is the most widely prescribed reliever inhaler in the UK. It is a pMDI device requiring slow, coordinated inhalation. A spacer significantly improves drug delivery and is recommended for all pMDI users. Key clinical points:

• Standard adult dose: 1–2 puffs on demand; up to 10 puffs via spacer in an acute attack
• Onset 2–5 minutes; duration 4–6 hours
• Reliever only — does not reduce airway inflammation
• Using more than twice weekly for symptom relief indicates inadequate asthma control
• Salamol Easi-Breathe is a breath-actuated pMDI alternative with simpler technique

For Ventolin-specific guides, see: Understanding and Using Your Ventolin Inhaler, Ventolin Evohaler: Your Essential Guide, and What Is a Ventolin Inhaler Used For?

Recognising and Responding to an Asthma Attack

An asthma attack occurs when symptoms worsen significantly and the usual reliever inhaler is not providing adequate or lasting relief. Knowing how to respond and when to escalate to emergency care is potentially life-saving.

Mild to Moderate Attack

1. Take 1 puff of reliever inhaler via spacer every 30–60 seconds, up to 10 puffs
2. Sit upright — do not lie down
3. Remain calm; reassure the patient if helping someone else
4. If symptoms improve, seek same-day GP or urgent care review
5. If no improvement after 10 puffs — call 999

For more on using Ventolin during breathlessness, see: Ventolin Inhaler: Relief for Shortness of Breath and Wheezing.

Asthma Self-Management

Written Asthma Action Plan

A personalised written plan developed with your GP or asthma nurse that tells you what to do when asthma is well controlled (green zone), worsening (amber zone), and in a severe attack (red zone). People with a written action plan are four times less likely to be admitted to hospital for asthma. Ask your GP or asthma nurse for one at your next review.

Annual Review

NICE recommends that all people with asthma have at least one structured review with their GP or asthma nurse every year — covering symptom control, inhaler technique, device suitability, adherence, and trigger avoidance. Access Doctor can support repeat prescribing between GP reviews for stable, well-controlled asthma.

Inhaler Technique

Up to 90% of patients make at least one critical inhaler technique error, dramatically reducing medication delivery to the airways. Check your technique at every asthma review. See: How to Use an Asthma Inhaler Correctly.

Smoking Cessation

Smoking reduces the effectiveness of ICS (preventer) inhalers and accelerates lung function decline. Stopping smoking is one of the most impactful changes a person with asthma who smokes can make.

Weight Management

Obesity is an independent risk factor for poorly controlled asthma. Even modest weight loss in overweight adults with asthma can improve symptom control and allow treatment to be stepped down.

Asthma Health Guides

In-depth clinical guides covering every aspect of asthma management — from understanding the condition to inhaler technique, Ventolin dosage, seasonal triggers, and advanced therapies.

Cornerstone guides

Clinical technique & treatment

Ventolin cluster

Depth, seasonal & advanced therapies