What should you know about bronchiolitis obliterans cause?

Small-airway injury may occur after a serious respiratory infection, inhalation of irritating fumes or chemicals, or certain medical treatments. It can also occur in association with immune-related illness or after an organ transplant. Sometimes no single cause is identified. Ongoing dry [Cough](/symptoms/cough/) and [Wheezing](/symptoms/wheezing/) can reflect many problems, so they do not establish bronchiolitis obliterans. The clinician will ask about timing, workplaces, hobbies, medicines, infections and any [Fever](/symptoms/fever/).

Write down when breathing symptoms began and what happened beforehand. Bring a list of medicines, previous lung illnesses and possible exposures to the appointment. Avoid smoke, vaping aerosol, solvents, dust and other fumes until the cause is clearer. Follow prescribed treatment exactly and do not borrow inhalers or use leftover antibiotics. A [Child Health Consultation](/treatments/consultations-and-assessment/child-health-consultation/) is a useful starting point for a child with persistent symptoms.

Get emergency help if breathing is severely difficult, lips look blue or grey, the person collapses, becomes confused or cannot speak in full sentences. Seek same-day advice when breathlessness is increasing, wheezing is sudden, or ordinary activity is no longer manageable. Do not delay care while trying to identify the original exposure. If a clinician recommends [Nebuliser Treatment](/treatments/acute-and-urgent-care/nebuliser-treatment/), use it only as instructed.

Ask which possible trigger matters most, whether an exposure should be reported or avoided, what tests can distinguish small-airway disease from asthma or infection, and how follow-up will measure breathing. Ask what symptoms require an urgent return.