What does bronchiolitis mean?
Bronchiolitis is a medical noun referring to inflammation of the bronchioles — the tiniest air passages in the lungs. Although the word can describe any inflammation of these small airways, it is overwhelmingly used for a common viral infection of infants and toddlers, most often triggered by respiratory syncytial virus (RSV). The illness typically begins with cold-like symptoms before producing a cough, wheezing, and sometimes breathing difficulty, and while most cases are mild and managed at home, severe cases can require hospitalization, particularly in very young babies. The word belongs firmly to clinical register: it appears in pediatric textbooks, hospital charts, and health guidance rather than casual speech. Its meaning is closely tied to winter months in temperate regions, when infections peak. Knowing the term helps distinguish it from bronchitis, which involves the larger airways and is more typical of adults and smokers.
nounInflammation of the bronchioles, the smallest branches of the airways in the lungs. In common usage it refers specifically to a viral infection causing such inflammation, most often affecting infants and young children.
- Inflammation of the bronchioles, especially as caused by viral infection in infants and young children.
"The infant was hospitalized with bronchiolitis after catching respiratory syncytial virus."
"The pediatrician diagnosed bronchiolitis and advised supportive care at home with close monitoring."
"Each winter, hospitals see a surge in admissions of infants suffering from bronchiolitis."
Bronchiolitis is so common that nearly all children have been infected by the virus behind it, RSV, by their second birthday — making it one of the most frequent reasons babies end up in hospital each winter.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bronchiolitis
Bronchiolitis derives from 'bronchiole', itself a diminutive of 'bronchus' from Latin 'bronchia', borrowed from Greek 'bronkhia', meaning the branches of the windpipe; the suffix '-itis' denotes inflammation and comes from Greek. The term was coined in medical Latin to name inflammation of these small airways. It shares its root with related terms such as bronchitis, bronchiole, and bronchiectasis.
How bronchiolitis is actually used
A clinical term used mainly in medical and healthcare contexts rather than everyday conversation. It carries no figurative or informal usage.
Easily confused with bronchiolitis
Bronchitis is inflammation of the larger bronchial tubes, whereas bronchiolitis is inflammation of the smaller bronchioles and typically affects infants.