Adventitious breath sounds
Fine crackles: brief, at the end of inspiration, at the bases. Fluid in the alveoli — heart failure, pneumonia, fibrosis. Coarse crackles: louder, lower pitched. Secretions in the larger airways. Wheezes: musical, mainly expiratory. Narrowed airways — asthma, COPD. Rhonchi: low pitched, snoring, clear or change with coughing. Secretions. Stridor: high pitched, inspiratory, audible without a stethoscope. Upper airway obstruction — an emergency. Pleural friction rub: creaking, unchanged by coughing, painful.