Regardless of the diagnosis, research has been unable to link disease severity with the quantity of crackles heard on exam. Conditions associated with crackles include cardiac disease, fibrotic lung disease, COPD, and pneumonia. Whereas the sudden opening of closed airways triggers a fine crackle, a coarse crackle is associated with the presence of secretions. A fine crackle has an increased frequency rate and quicker duration than a course crackle. These sounds are most often heard at the base of the lungs. Crackles can be categorized as coarse or fine and may occur during either, or both, inspiration and expiration. Unlike a wheeze, it is not musical in nature. Of note, healthy patients can often produce a benign wheeze during forced expiration.Ĭrackleis an explosive short sound. Wheezing may be a single sound or a multitude of sounds, and although its presence may be diagnostic for airflow obstruction, its absence does not rule anything out.Ĭonditions associated with wheezing include viral illnesses such as bronchiolitis, croup, and whooping cough asthma chronic obstructive pulmonary disease (COPD) cystic fibrosis bronchiectasis pulmonary edema foreign body aspiration or tracheal or laryngeal tumors. The timing of an adventitious sound within the respiratory cycle is a diagnostic identifier and should be noted during an exam. A wheeze may occur during either, or both, of the inspiratory and expiratory phases of the respiratory cycle. The fluctuation of opposing airway walls being tightened nearly to a point of contact generates the sound. Wheezingis often described as a musical note.

Because each of these adventitious breath sounds may be present with one or more diagnoses, it is important to make note of the abnormality in context with the patient’s history and clinical exam. Bronchial sounds are best heard over the body of the sternum.Ībnormal breath sounds are often indicators of pathology in the airways and include wheezing, crackle, rhonchi, stridor, and plural rub. Bronchovesicular breath sounds are best heard between the first and second intercostal spaces of the anterior chest. Tracheal sounds are heard best over the trachea and typically are louder and have a higher pitch than vesicular sounds. In airfilled lungs, vesicular breath sounds are commonly heard over the majority of the lung fields. Normal breath sounds can be heard throughout the lung fields in a healthy patient and are most often classified as 1 of 4 types: vesicular, tracheal, bron- chosvesicular, and bronchial. There is often confusion between breath and voice sounds breath sounds generate in the lungs whereas voice sounds generated in the larynx.

During this process, Laënnec invented the stethoscope.īreath sounds are categorized as normal or abnormal and have 3 characteristics: intensity (soft, medium, loud, very loud), pitch (low, medium, high), and duration. René Théophile-Hyacinthe Laënnec established the link between a breath sound and an identifiable pathological change in the lungs. Auscultation, a technique that requires both clinical experience and a good stethoscope, dates back to the early 1800s.

“Breath sounds” refer to the movement of air through the respiratory system and can be evaluated through auscultation of the lung fields.

Lung breath sounds