Bronchial asthma is a chronic inflammatory disease of the airways. It is defined by recurring symptoms and reversible obstruction. Below: the mechanism, symptoms, triggers, and diagnosis, without treatment regimens.
What happens in the bronchi
Asthma is caused by inflammation and contraction of the muscles around the airways. Breathing becomes harder.
The mechanism is as follows. Small and medium bronchi contract spasmodically. The spasm occurs due to reflex irritation of the vagus nerve. At the same time, more mucus is produced. The mucous membrane swells. The lumen of the bronchi narrows.
This is a chronic disease in children and adults. Among children, it is the most common chronic disease.
Asthma is a common non-communicable disease. In 2023, it affected approximately 363 million people. That same year, it caused 442,000 deaths.
Symptoms and daily variability
Typical symptoms: cough, wheezing, shortness of breath, chest tightness. They can be mild or severe. Symptoms come and go.
The cough is often persistent, especially at night. Wheezing is heard on exhalation, sometimes on inhalation. Shortness of breath can occur even at rest.
Daily variability is a key sign. Symptoms worsen at night and early in the morning. They flare up after physical exertion or in cold air. Because of symptoms, a person wakes up at night. Untreated asthma causes sleep disturbance, daytime fatigue, and poor concentration.
Symptoms differ from person to person. Sometimes they intensify significantly — this is an asthma attack. Some people have symptoms rarely, in response to an irritant. Others have pronounced and persistent symptoms.
Triggers
A trigger is an irritant that sets off symptoms. The main groups are as follows.
- Allergens: dust, grass and tree pollen, animal fur and feathers, mold.
- Cold air and weather changes.
- Physical exertion.
- Smoke, fumes, air pollution, strong detergents and perfumes.
- Viral infections: during a cold, symptoms become more frequent.
Some medications for other conditions can set off symptoms; this is checked with a doctor.
Who is at risk
Asthma is more common if close relatives have it — a father, mother, brother, or sister. The risk is higher with other allergic conditions, such as eczema and allergic rhinitis. Risk is influenced by early-life events: low birth weight, prematurity, tobacco smoke, air pollution, viral respiratory infections. Dust mites, mold, and contact with chemicals, fumes, or dust at work add to the risk. Adults and children with excess weight are affected more often.
How the diagnosis is confirmed
The diagnosis relies on the clinical picture, response to therapy over time, and spirometry. The doctor asks questions, listens to the chest, and may order a simple breathing test. Sometimes a blood test is needed.
Spirometry measures the forced expiratory volume in one second — FEV1. Peak flow measurement shows the peak expiratory flow rate. A peak flow meter is given to take home for several weeks to assess lung function.
The diagnosis is sometimes not made immediately. Symptoms are variable, and breathing problems have various causes.
Exacerbations and prevention
An asthma attack means severe symptoms and difficulty breathing. It can be life-threatening.
Call 103 or 112 if during an attack: the condition worsens at any time; there is no relief after a quick-relief inhaler used according to the individual plan; there is no inhaler at all.
After an attack, even if it has eased, see a family doctor within 2 days. This is a scheduled consultation, not an emergency call.
Avoiding triggers reduces symptoms: air pollution, smoke, pollen, animals.
Reducing tobacco smoke lowers the risk of new cases and makes the disease easier to control. Most asthma deaths occur in low- and lower-middle-income countries. There, diagnosis and treatment are lacking.
Scheduled check-ups at least once a year show whether the chosen therapy is helping and whether the inhaler is being used correctly.
Terms: obstruction — narrowing of the bronchial lumen; FEV1 — forced expiratory volume in the first second; spirometry — a breathing test measuring FEV1; peak flow measurement — measurement of peak expiratory flow rate; trigger — an irritant that sets off symptoms.
This material is for reference and does not replace a doctor's consultation.
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This content is for reference and does not replace a doctor's consultation. Medical disclaimer