What causes asthma?

There is often no single cause. The underlying airway sensitivity is different from a trigger, which is something that brings on symptoms in a person who already has asthma.

In asthma, the lining of the breathing tubes becomes inflamed, muscles around the tubes tighten, and mucus may increase. This reduces airflow and can produce wheezing, cough, chest tightness or shortness of breath. Asthma commonly presents with these symptoms, but symptoms can vary from one episode to another.

A family tendency to asthma or allergy can increase susceptibility. Smoke, dust mites, pollen, respiratory infections, exercise, cold air, strong scents and workplace irritants may provoke symptoms. Identifying a trigger does not mean it originally caused the condition.

Arrange a clinical assessment if asthma is suspected. A clinician may review the pattern of symptoms, listen to the chest and use breathing tests to look for variable airflow limitation. Keep a note of when symptoms occur, possible exposures, night waking and how often a reliever inhaler is needed.

Follow the written asthma action plan provided for you. Use inhalers with the prescribed technique, avoid tobacco smoke, and discuss realistic ways to reduce confirmed triggers. Do not stop a preventer medicine simply because breathing feels better.

Seek emergency help for severe breathlessness, difficulty speaking in full sentences, blue or grey lips, confusion, faintness, marked chest pulling with each breath, or symptoms that keep worsening despite following the emergency steps in the asthma action plan. Sit upright and use prescribed rescue treatment while help is being arranged.

Request a prompt medical review when symptoms wake you, limit normal activity, recur frequently, or require more reliever medicine than the plan allows. These changes can signal that airway inflammation is not adequately controlled.

Ask what findings support the diagnosis, whether breathing tests are appropriate, which triggers are worth investigating, and how to distinguish daily preventer treatment from rescue treatment. Have your inhaler technique checked and request clear instructions for worsening symptoms.