airway sounds

Wheezes

High-pitched, musical, or whistling sound (usually on expiration). Caused by lower airway constriction in asthma, COPD, or anaphylaxis.

Rales (Crackles)

Fine or coarse wet, popping, or crackling sounds (usually on inspiration). Caused by fluid in the alveoli or small airways popping open in CHF, pulmonary edema, or pneumonia.

Rhonchi

Low-pitched, heavy, rattling, or snoring sounds. Caused by thick mucus or secretions in the larger lower airways in bronchitis, pneumonia, or COPD.

Stridor

High-pitched, harsh, seal-like crowding sound (usually on inspiration). Caused by partial obstruction of the upper airway (trachea/larynx) in croup, epiglottitis, or foreign body obstruction.

Absent / Diminished

Severely decreased or missing breath sounds over a lung field. Indicates little to no air movement due to severe pneumothorax, hemothorax, or severe asthma attack.