During a respiratory examination, doctors often use a stethoscope to listen to the lungs while a patient breathes. This helps assess airflow and detect abnormal sounds related to the airways or lung tissue. Master of Science, Doctor Dang Thanh Do of Tam Anh General Hospital, Hanoi, identified four common types of abnormal lung sounds: rhonchi, crackles, moist rales, and wheezing.

Rhonchi

Rhonchi are low-pitched sounds, often described as snoring or gurgling. These sounds are clearer during exhalation and may temporarily decrease after coughing.

Rhonchi occur when large airways are obstructed by phlegm, secretions, or mucus. They are commonly associated with conditions that cause increased phlegm production or airway narrowing, such as bronchial asthma, pneumonia, bronchiectasis, and chronic obstructive pulmonary disease (COPD).

Doctor Do (right) listens to a patient's heart and lungs. Photo: Tam Anh General Hospital

Doctor Do (right) listens to a patient's heart and lungs. Photo: Tam Anh General Hospital

Crackles

Crackles are small, intermittent sounds, similar to the crackling of salt being roasted. They are typically heard clearly during inhalation.

Crackles occur when alveoli suddenly open, creating a characteristic popping sound. Unlike rhonchi, crackles usually do not disappear after coughing.

This type of sound is often related to lung tissue damage or fluid accumulation in the alveoli, found in pneumonia, bronchiectasis, and interstitial lung disease.

Moist rales

Moist rales sound like gurgling or bubbling as air passes through secretions (phlegm, fluid) in the airways. These sounds may change or disappear entirely with coughing.

Based on their pitch heard through a stethoscope, moist rales are categorized into three basic types: fine moist rales (small popping sounds originating from alveoli and terminal bronchioles), medium moist rales (sounds like simmering water, originating from small bronchi), and coarse moist rales (sounds like bursting bubbles, originating from large bronchi).

These sounds are often heard in cases of pneumonia, pulmonary edema, and heart failure.

Wheezing

Wheezing results from widespread bronchial constriction, extending from large to small bronchi. The sound is high-pitched, and its intensity depends on the degree of bronchial constriction. Wheezing is clearer during exhalation and is commonly observed in bronchial asthma and chronic obstructive pulmonary disease.

Thuy Duong