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What are the types of abnormal breath sounds?


Normal breath sounds (vesicular sounds) Inspiratory phase longer than expiratory phase, without interposed gap. Due to transmitted air turbulence.
Bronchial breathing Harsher noises; prolonged during expiration. Heard over areas of consolidation, where sound is not filtered by alveoli.
Amphoric breath sounds (less common) Hollow noises, heard over a large cavity. The sound is said to be like the noise of air passing over the top of a hollow jar.
Reduced intensity (decreased air entry) Muffled breath sounds as a result of pleural effusion, pneumonia, chronic obstructive pulmonary disease collapse, pneumothorax or a mass.
Added sounds
Wheeze (polyphonic) Continuous sounds with a musical quality. Note when in the respiratory cycle the wheeze occurs; usually louder in expiration. Due to airway narrowing in asthma or chronic obstructive respiratory disease.
Wheeze (monophonic) Single note, due to fixed obstruction such as a space occupying lesion.
Stridor Unlike wheeze, stridor is inspiratory; due to upper airway obstruction
Crackles Interrupted, non-musical sounds, often occurring due to opening of small airways. Early inspiratory crackles suggest chronic obstructive respiratory disease; whilst later or pan-inspiratory crackles suggest that the disease is limited to the alveoli.Fine crackles sound like Velcro being pulled apart, they are characteristic of pulmonary fibrosis; medium crackles are typical of left ventricular failure whilst coarse crackles indicate pools of retained secretions in conditions such as bronchiectasis.
Pleural rub A continuous grating sound which occurs with pleurisy as the inflamed pleura rub against each other (e.g. secondary to a pulmonary infarct or pneumonia)


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