Asthma

Asthma attacks can become life-threatening. Follow the person’s written asthma action plan and seek emergency care if breathing is severely difficult, the prescribed reliever is not helping, normal walking or talking is difficult, or the lips or fingernails look blue, pale or grey. Drowsiness, confusion or rapidly worsening symptoms also require urgent emergency assessment.

What is asthma?

Asthma is a long-term lung disease in which inflammation and tightening of muscles around the airways make it harder to breathe. The airways can also produce more mucus. Symptoms usually vary over time: they may disappear between episodes and then return after exposure to a trigger. Asthma affects children and adults and can range from mild to severe.

Common symptoms include wheezing, coughing, shortness of breath and chest tightness. Symptoms may be worse at night, during exercise or with a respiratory infection. Other conditions can cause similar symptoms, so recurrent breathing problems should be assessed rather than self-diagnosed.

Why asthma develops

There is rarely one direct cause. Asthma reflects interactions between genetic susceptibility, immune responses, lung development and environmental exposures. A close family history of asthma and allergic conditions such as eczema or allergic rhinitis can increase risk. Prematurity, tobacco smoke, air pollution, some early respiratory infections and occupational exposures are also associated with asthma.

Asthma is not simply the result of a child being “too clean,” and it is not the person’s fault. The relationship between microbes, the developing immune system and asthma is complex and does not support deliberately exposing a child to infection or poor hygiene.

Triggers and patterns

A trigger can worsen symptoms in someone who already has asthma. Triggers differ between people and can change over time. Common examples include viral respiratory infections, tobacco smoke, air pollution, pollen, mould, dust mites, animal allergens, cold air, strong fumes and exercise. Strong emotion can alter breathing and contribute to symptoms, but asthma is not a psychological illness.

Some people have predominantly allergic asthma, while others have symptoms without an obvious allergy. Work-related asthma can be caused or worsened by dusts, chemicals, fumes, latex, flour, animal proteins and other substances. Symptoms that improve away from work need prompt clinical assessment because early removal from the responsible exposure may protect lung function.

Exercise-induced bronchoconstriction means that activity temporarily narrows the airways. It should not automatically lead to avoiding exercise: with good control, suitable preparation and the person’s prescribed plan, most people with asthma can remain active. Aspirin, some non-steroidal anti-inflammatory medicines and beta blockers can worsen asthma in susceptible people; suspected medicine reactions need individual medical advice rather than blanket avoidance.

How asthma is diagnosed

Diagnosis combines a history of variable respiratory symptoms with objective evidence that airflow out of the lungs varies. Where available, spirometry is measured before and after a bronchodilator. A clinician may repeat testing when symptoms are present, monitor peak-flow variation over time or use other tests when initial spirometry is normal. Testing and interpretation differ for young children and for people already using inhaled corticosteroids.

Assessment also considers allergies, smoking or vaping exposure, work, medicines, reflux, rhinitis and other conditions that may mimic or worsen asthma. A stethoscope examination can be useful, but a normal examination between episodes does not rule asthma out.

Control and future risk

Asthma is not usefully managed by asking readers to place themselves in a fixed severity category. Clinicians assess current symptom control and the risk of future attacks, then review the response to treatment. Important clues to poor control include night waking, activity limitation, frequent reliever use and recent exacerbations. Lung function, inhaler technique, adherence, exposure to triggers and other health conditions also matter.

Treatment

Treatment should be individualized for age, symptoms, attack history, local medicine availability, pregnancy and other health conditions. The plan should be reviewed after treatment changes and at regular intervals. Do not start, stop or change a prescribed inhaler on the basis of a general article.

Inhaled corticosteroid-containing treatment

Inhaled corticosteroids reduce airway inflammation and the risk of severe attacks. Current GINA guidance recommends that adults and adolescents should not be treated with a short-acting beta agonist (SABA) reliever alone. For many adults and adolescents, the preferred approach uses low-dose inhaled corticosteroid–formoterol as the reliever, with the exact schedule depending on treatment step. Alternative corticosteroid-containing regimens are used when this option is unsuitable or unavailable. Children require age-specific plans.

Correct inhaler technique is essential. A clinician, nurse or pharmacist should watch the person use the device and correct errors. A spacer can improve delivery from a pressurized metered-dose inhaler. Rinsing the mouth after an inhaled corticosteroid may reduce local side effects when advised for that device.

Other controller and add-on treatments

Depending on response, clinicians may use a daily inhaled corticosteroid, an inhaled corticosteroid combined with a long-acting bronchodilator, or selected add-on treatments. A long-acting muscarinic antagonist or a biologic medicine may be considered for some people whose asthma remains uncontrolled after diagnosis, technique and adherence have been reassessed.

Montelukast is useful in selected patients but carries an FDA boxed warning about serious mood and behaviour effects. Anyone prescribed it should receive counselling about the warning and promptly discuss new neuropsychiatric symptoms with a healthcare professional. Benefits and risks must be considered for the individual.

Managing an attack

Use the reliever and other treatment exactly as written in the personal action plan. Ipratropium may be added by clinicians in some severe acute attacks; it does not work in the same way as a SABA. Short courses of oral corticosteroids may be prescribed for significant exacerbations, while intravenous treatment belongs in supervised acute care. Repeated corticosteroid courses can cause harm and should prompt review of long-term control.

Written action plan and follow-up

Every person with asthma should have a written, digital or pictorial action plan created with a healthcare professional. It should state the usual medicines, how to recognize worsening asthma, what changes to make and when to seek medical or emergency care. The plan must reflect the person’s actual inhalers; a generic dose schedule is unsafe.

Regular review should include symptoms, attacks, lung function when appropriate, inhaler technique, adherence and barriers to care. More frequent symptoms or reliever use, night waking, missed work or school, or reduced activity are reasons to arrange review rather than simply continuing the same treatment.

Reducing the risk of attacks

• Take prescribed corticosteroid-containing treatment and keep the action plan accessible.
• Avoid tobacco smoke and seek support to stop smoking or vaping.
• Identify personal triggers without imposing unnecessary restrictions.
• Discuss vaccines appropriate for age and health conditions according to local guidance.
• Address work exposures promptly and use appropriate occupational-health support.
• Maintain physical activity within the individualized asthma plan.

Asthma itself is not always preventable, but many attacks can be prevented. With an accurate diagnosis, access to appropriate inhaled treatment, correct technique, regular review and a clear action plan, most people can control symptoms and lead active lives. Severe attacks can still occur, including in people with infrequent symptoms, so emergency warning signs should never be ignored.