Asthma causes: what patients should know

The airways of a person with asthma become inflamed and react strongly to certain exposures. During a flare, muscles around the breathing tubes tighten and the lining can swell and produce mucus, making airflow more difficult.

An underlying tendency to asthma can run in families and is often associated with allergic conditions. Tobacco smoke exposure, air pollution and some workplace substances may also contribute to the development or worsening of sensitive airways.

A trigger is something that sets off symptoms in airways that are already sensitive. Common examples include dust mites, pollen, pets, smoke, respiratory infections, cold air, exercise and strong fragrances. A trigger does not affect everyone in the same way, and a person may have several triggers.

Asthma commonly presents with wheezing, cough, chest tightness or shortness of breath that varies over time. These symptoms also occur with other health problems, so their pattern and response to assessment matter.

Record when symptoms begin, what you were doing, where you were and whether you had a cold or allergy symptoms. Include night waking, limits on activity and use of a reliever inhaler. This gives a clinician a clearer picture than a single symptom snapshot.

Reduce avoidable smoke and irritant exposure, but do not make major changes such as removing a pet or leaving a job based only on suspicion. A clinical review can connect the history with breathing tests and, when appropriate, allergy or workplace assessment.

Seek emergency help if breathlessness is severe, you cannot speak comfortably in full sentences, your lips or face look blue or grey, you feel confused or exhausted, or your prescribed reliever is not helping. Follow your personal asthma action plan while help is arranged.

Arrange a prompt medical review when symptoms are waking you, restricting usual activity, recurring after a particular exposure or requiring the reliever more often than your plan advises. These changes can signal that airway inflammation is not well controlled.

Ask which features of your history support asthma, whether breathing tests are suitable, how to distinguish a trigger from an underlying cause, and which exposures are realistic to reduce. Also request a written action plan explaining daily treatment, worsening symptoms and emergency steps.