Skip to main content

Rare lung & airway condition

Bronchiolitis obliterans

Bronchiolitis obliterans is scarring and obliteration of the smallest airways, causing fixed airflow obstruction; it follows transplantation, severe infections, toxic inhalations or autoimmune disease.

Key points

The essentials at a glance.

What to look out for, how the diagnosis is confirmed, who looks after it, and the options that exist.

  • 01

    Symptoms are progressive breathlessness and wheeze that do not respond to asthma treatment.

  • 02

    Spirometry shows fixed obstruction; CT with expiratory views reveals characteristic air trapping.

  • 03

    Recognised settings: after stem-cell or lung transplantation (as graft-versus-host disease or chronic rejection), post-infectious in childhood, inhalational injury, and rheumatoid disease.

  • 04

    Treatment is difficult - azithromycin, inhaled therapy and managing the underlying driver; transplant-related disease has specific protocols.

  • 05

    Early specialist referral matters because established obliteration is irreversible.

Understanding it

What it is, and what happens next.

In plain English - what is going on, how specialists confirm it, and the routes to treatment in the UK.

The bronchioles - airways narrower than a pencil lead - can respond to severe injury by scarring shut entirely. Because they are too small to see on plain imaging and their loss mimics asthma or COPD, bronchiolitis obliterans is habitually diagnosed late, after inhalers have failed and the spirometry refuses to budge.

The diagnostic keys are a story that fits - a transplant, a notorious infection, a toxic exposure, longstanding rheumatoid arthritis - plus expiratory CT and detailed lung function; specialist respiratory care then aims to stabilise rather than cure, using azithromycin and cause-specific measures, with transplantation itself the last resort for relentless decline. In many parts of the UK, routine NHS outpatient referrals for problems like this can take several months, whereas an initial appointment with a private consultant is typically available within around two weeks.

A quiet reminder

This guide is for information, not medical advice.

Your GP or specialist knows your history and can tell you which parts apply to you. If in doubt, speak to them.

Published 2026-09-27 · Next review 2027-09-27

Frequently asked

Common questions about Bronchiolitis obliterans.

Quick, plain-English answers to what people ask us most.

  • What is bronchiolitis obliterans?

    Bronchiolitis obliterans is an infection that develops when bacteria, viruses or other organisms invade the affected tissue and trigger inflammation. Severity varies widely, from a mild, self-limiting illness to a more serious infection that needs prompt treatment. The specific organism responsible, and how quickly it is identified, has a big influence on the best treatment.

  • What causes bronchiolitis obliterans?

    Bronchiolitis obliterans is caused by an infectious organism, which may be bacterial, viral or fungal depending on the specific condition. It can spread through close contact, contaminated surfaces, insect bites, or from another site of infection in the body. People with a weakened immune system, chronic illness or certain risk factors are generally more susceptible.

  • What are the symptoms of bronchiolitis obliterans?

    Symptoms of bronchiolitis obliterans vary from person to person and depend on how severe the condition is and which structures are affected. Some people notice symptoms gradually over weeks or months, while others experience a more sudden onset. Because symptoms can overlap with other conditions, a proper assessment is important to reach an accurate diagnosis rather than relying on symptoms alone.

  • Is bronchiolitis obliterans serious or dangerous?

    Most cases of bronchiolitis obliterans are manageable, especially when identified and treated early, but severity varies from mild and self-limiting to more significant, depending on individual circumstances. Left unassessed, some cases can lead to complications or a longer-term impact on daily life. If you are worried about your symptoms, it is always worth getting them checked rather than waiting.

  • Is bronchiolitis obliterans contagious or can it come back?

    Whether bronchiolitis obliterans can be passed on or can recur depends on the specific cause and how well any underlying trigger is managed. Some cases are a one-off, while others can flare again if you are re-exposed to the same trigger or organism. Your clinician can advise on the specific risk of recurrence in your case and any steps that reduce it.

  • Can bronchiolitis obliterans be cured, reversed or prevented?

    Outlook varies with bronchiolitis obliterans: some cases resolve completely with treatment, others improve significantly but need ongoing management, and a smaller number become a long-term condition to be controlled rather than cured. Prevention strategies, such as addressing modifiable risk factors, can reduce your chances of developing it or of it recurring, but cannot guarantee against it in every case.

  • How is bronchiolitis obliterans treated?

    Treatment for bronchiolitis obliterans is tailored to the individual and depends on severity, underlying cause and personal circumstances. Options can range from simple lifestyle measures, monitoring and conservative treatment through to medication, specialist procedures or surgery in more significant cases. A specialist assessment helps identify which combination of treatments is most appropriate for you.

  • How long does bronchiolitis obliterans last?

    The duration of bronchiolitis obliterans varies considerably: some people recover within days or weeks, while others live with a more persistent or recurring condition that needs ongoing management. Response to treatment, how early it is started, and individual factors all influence the timescale. Your clinician can give you a more personalised estimate once your specific circumstances are known.

  • When is surgery needed for bronchiolitis obliterans?

    Surgery is not usually the first option for bronchiolitis obliterans and is generally reserved for cases where conservative treatment has not worked, symptoms are severe, or there is a significant structural problem that needs to be corrected directly. The decision depends on your specific findings, symptoms and how they are affecting your life. A specialist consultation is the best way to establish whether surgery is being considered too early, or should be considered sooner rather than later.

  • When should I see a doctor about bronchiolitis obliterans, and how quickly can I be seen privately?

    It is worth seeing a doctor about bronchiolitis obliterans if symptoms are persistent, getting worse, or affecting your daily life, rather than waiting to see if they settle on their own. NHS routine referrals to a specialist can currently take anywhere from around 20 to 45 weeks or more depending on your area, whereas a private consultant can typically see you within about 2 weeks. Getting an earlier assessment can help clarify the diagnosis and start the right treatment sooner.