[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Clinical exam](https://durgical.com/en/clinical-exam/) › [Respiratory system](https://durgical.com/en/clinical-exam/#a-respiratory) › Bronchial obstruction syndrome [Clinical exam](https://durgical.com/en/clinical-exam/) · [Respiratory system](https://durgical.com/en/clinical-exam/#a-respiratory) # Bronchial obstruction syndrome - Syndrome The airways narrow and air is hard to breathe out: long expiration, wheezes and a chest that fills with air. Updated 2026-11-01 **See it in 3D:** [Main bronchi](https://durgical.com/en/anatomy/right-main-bronchus/) · [Lobar bronchi](https://durgical.com/en/anatomy/lobar-bronchus/) · [Segmental bronchi](https://durgical.com/en/anatomy/segmental-bronchus/) ## Key points - Prolonged expiration and diffuse expiratory wheezes: bronchial obstruction. - Wheezes in both phases mean more severe obstruction than expiratory wheezes alone. - Silent chest, inability to speak, drowsiness or cyanosis: a severe attack at risk of respiratory failure. - Asthma: episodic, with triggers, reversible. COPD: progressive, with cigarette or wood-smoke exposure. - Bilateral, symmetric findings: hyperresonance, reduced fremitus and reduced breath sounds. - Spirometry confirms obstruction (a low ratio of volume exhaled in the first second to forced vital capacity). ## What it is Bronchial obstruction syndrome groups the findings of diffuse narrowing of the intrathoracic airways from bronchospasm, inflammation, mucus or loss of elastic support. Air gets in more easily than it gets out, is trapped and causes hyperinflation. The main causes are asthma and COPD; in infants, bronchiolitis. ## Key findings - A localized, fixed wheeze is not asthma: look for focal obstruction. - Stridor (upper airway) must not be mistaken for wheezes: it is loudest over the neck and inspiratory. ## Pathophysiology - The bronchial lumen narrows from smooth muscle contraction, wall oedema and inflammation, and mucus. - On expiration the airways narrow further; air is trapped and the lung hyperinflates. - Fast air through narrow bronchi makes the walls vibrate and produces wheezes. - Trapping flattens the diaphragm and raises the work of breathing, which recruits the accessory muscles. | Inspection | Palpation (fremitus) | Percussion | Auscultation | | --- | --- | --- | --- | | [Asthma attack: tachypnea, accessory muscles, retractions; trachea midline](https://durgical.com/en/conditions/asthma/) | Reduced fremitus on both sides | Bilateral hyperresonance | Expiratory or biphasic wheezes; prolonged expiration | | [COPD: barrel chest, pursed lips, Hoover sign](https://durgical.com/en/conditions/chronic-obstructive-pulmonary-disease/) | Reduced fremitus on both sides | Hyperresonance; low bases | Reduced breath sounds, prolonged expiration, wheezes or rhonchi | ## Common causes - Asthma. - COPD (chronic bronchitis and emphysema). - Bronchiolitis in infants. - Acute bronchitis with bronchospasm, bronchiectasis. - Heart failure with bronchial oedema ('cardiac asthma'). ## Tests that confirm it - Spirometry with a bronchodilator test. - Peak expiratory flow for asthma follow-up. - Oxygen saturation and arterial blood gases in a severe attack. ## Memory aid Easy in, hard out: trapped air lengthens expiration and makes the bronchi whistle. ## Test yourself Think of the answer, then tap the question to see it. ## Why is expiration prolonged in bronchial obstruction? Because the airways narrow further on expiration and air leaves slowly, becoming trapped. ## What does a silent chest mean in an asthma attack? Airflow so low it makes no wheezes: severe obstruction with fatigue and risk of respiratory failure. ## Which test confirms airflow obstruction? Spirometry, showing a low ratio of volume exhaled in the first second to forced vital capacity. ## Which clinical difference separates asthma from COPD? Asthma is episodic, triggered and reversible; COPD is progressive, follows cigarette or wood-smoke exposure and is only partly reversible. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/clinical-exam/bronchial-obstruction-syndrome/) ## See it in 3D The structures of Durgical's 3D anatomy where it is found. - [Main bronchi](https://durgical.com/en/anatomy/right-main-bronchus/) - [Lobar bronchi](https://durgical.com/en/anatomy/lobar-bronchus/) - [Segmental bronchi](https://durgical.com/en/anatomy/segmental-bronchus/) ## Related - [The pleuropulmonary syndromes: the comparison table to know](https://durgical.com/en/clinical-exam/the-pleuropulmonary-syndromes-the-comparison-table-to-know/) - [Adventitious sounds: crackles, wheezes, rhonchi, stridor and pleural rub](https://durgical.com/en/clinical-exam/adventitious-sounds-crackles-wheezes-rhonchi-stridor-and-pleural-rub/) - [Pulmonary hyperinflation syndrome (emphysema)](https://durgical.com/en/clinical-exam/pulmonary-hyperinflation-syndrome/) - [Respiratory distress and respiratory failure: the signs](https://durgical.com/en/clinical-exam/respiratory-distress-and-respiratory-failure-the-signs/) - [Respiratory rate and breathing patterns](https://durgical.com/en/clinical-exam/respiratory-rate-and-breathing-patterns/) ## Related conditions - [Asthma](https://durgical.com/en/conditions/asthma/) - [Chronic obstructive pulmonary disease (COPD)](https://durgical.com/en/conditions/chronic-obstructive-pulmonary-disease/) - [Bronchiolitis (RSV)](https://durgical.com/en/conditions/bronchiolitis/) - [Croup (laryngotracheobronchitis)](https://durgical.com/en/conditions/croup/) - [Acute bronchitis](https://durgical.com/en/conditions/acute-bronchitis/) [← All of the clinical exam](https://durgical.com/en/clinical-exam/) Educational content on the clinical exam; it is learned and practised under supervision. It does not replace assessment by a health professional and is not for self-diagnosis. Sources: [Asthma: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000141.htm) (MedlinePlus, U.S. National Library of Medicine, 2024); [Chronic obstructive pulmonary disease (COPD): MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000091.htm) (MedlinePlus, U.S. National Library of Medicine, 2024); [Breath sounds: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/007535.htm) (MedlinePlus, U.S. National Library of Medicine, 2024). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/clinical-exam/bronchial-obstruction-syndrome/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/clinical-exam/bronchial-obstruction-syndrome/