🩺 Wheeze

Wheeze is a high-pitched, musical adventitious lung sound produced by air flowing through narrowed small airways. It is a hallmark symptom of obstructive lung diseases, most commonly asthma and COPD. While often associated with reversible bronchospasm, it can also result from mucosal oedema or mechanical obstruction. Clinical evaluation focuses on identifying the underlying cause and assessing the severity of respiratory compromise to prevent acute respiratory failure.

Establish the onset (acute vs chronic) and triggers (exercise, cold air, allergens, occupational insults). Ask about diurnal variation, specifically nocturnal or early morning symptoms, which are classic for asthma. Distinguish from 'stridor' (a high-pitched inspiratory sound indicating upper airway obstruction). Clarify smoking status and family history of atopy (eczema, hay fever). Review current inhaler use and technique, and ask about previous hospitalisations or ICU admissions for respiratory distress.

Assess the work of breathing, including the use of accessory muscles (sternocleidomastoids, intercostals) and the presence of tracheal tug. On auscultation, note whether the wheeze is inspiratory or expiratory (wheeze is typically expiratory; inspiratory sounds are often stridor). Listen for the 'polyphonic' nature typical of asthma. Measure oxygen saturations and heart rate (tachycardia may indicate severity or beta-agonist use). Examine the peripheries for cyanosis or signs of right-sided heart failure (raised JVP, ankle oedema) which may suggest COPD/Cor Pulmonale.

Asthma, COPD, Anaphylaxis, Acute Heart Failure (Pulmonary Oedema), Bronchiectasis, Lung Cancer (fixed wheeze), Foreign Body Aspiration, Bronchiolitis (in infants).

Silent chest, inability to complete sentences, cyanosis, exhaustion/confusion (rising CO2), monophonic wheeze (suggests localized obstruction), or sudden onset with urticaria (anaphylaxis).

Bedside tests include peak expiratory flow (PEFR) and pulse oximetry. For chronic diagnosis, spirometry with reversibility testing or FeNO (Fractional exhaled Nitric Oxide) is recommended by NICE for asthma. In the acute setting, an arterial blood gas (ABG) is required if saturations are low or the patient is tiring (a 'normal' pCO2 in an acute asthma attack is a life-threatening sign). Chest X-ray should be performed to exclude pneumonia, pneumothorax, or heart failure if the diagnosis is unclear or the patient fails to improve.

'Silent' wheeze is a medical emergency; the absence of wheeze in an acutely breathless patient suggests the airway is too tight to move enough air to produce sound. Not all that wheezes is asthma; heart failure ('cardiac asthma') can cause wheeze due to peribronchial oedema, and a localised, monophonic wheeze should always prompt investigation for a fixed airway obstruction like a tumour or foreign body. Polyphonic wheeze (multiple pitches) usually indicates diffuse small airway disease like asthma or COPD. Assessment of speech (full sentences vs broken words) is the best clinical indicator of severity.

Aligned with the MLA content map 'Wheeze'. Emphasise the differential between asthma and COPD using NICE (NG80/NG115) criteria. Recognising the 'silent chest' as a life-threatening sign in acute asthma is a frequent exam point. Understand the stepwise management of asthma and COPD in both chronic and emergency settings.