Rhonchi are a specific type of abnormal lung sound detected by a healthcare provider using a stethoscope. These sounds are characterized as low-pitched and continuous, occurring as air moves through the larger airways of the respiratory system. The presence of rhonchi is not a disease itself but rather a clinical sign that points toward an underlying respiratory issue.
What Rhonchi Sounds Like
The sound of rhonchi is often compared to snoring or a low-pitched gurgling noise. This auditory quality is produced when air flows through the larger airways, known as the bronchi, which are partially obstructed. The obstruction is caused by secretions, such as mucus, that accumulate in these passages, creating turbulent airflow that vibrates the airway walls.
Rhonchi can be contrasted with wheezes and crackles. Wheezes are high-pitched, musical sounds that result from the narrowing of smaller airways, often heard in conditions like asthma. Crackles are brief, popping sounds produced when small, collapsed air sacs snap open, usually due to fluid in the lungs. Rhonchi are lower in pitch than wheezes and more continuous than the short, intermittent nature of crackles, reflecting their origin in the larger, mucus-filled bronchial tubes.
Common Causes of Rhonchi
Several medical conditions are associated with the production of rhonchi because they lead to increased mucus or inflammation in the larger airways. Acute bronchitis, which is inflammation of the bronchial tubes often caused by a viral infection, is a frequent cause. The inflammation triggers the production of excess mucus, which obstructs the airways and generates the characteristic sound as air passes through.
Pneumonia, an infection that inflames the air sacs in one or both lungs, can also cause rhonchi. While pneumonia is often associated with crackles due to fluid filling the smaller alveoli, it can also cause inflammation and mucus production in the larger bronchi. This occurs when the infection affects the bronchial passages and the lung tissue.
Chronic Obstructive Pulmonary Disease (COPD), a progressive lung disease that includes chronic bronchitis and emphysema, is another cause. In the chronic bronchitis component of COPD, the bronchial tubes are persistently inflamed and produce a large amount of mucus daily. This chronic obstruction creates the conditions for rhonchi to be heard.
Cystic fibrosis, an inherited disorder, significantly impacts the respiratory system by causing the body to produce unusually thick and sticky mucus. This thick mucus clogs the airways, including the large bronchi, leading to persistent obstruction and recurrent infections. This dense mucus makes rhonchi a common finding for individuals with this condition.
Medical Evaluation and Management
A diagnostic feature of rhonchi is that the sound may change or even clear temporarily after the patient coughs. This occurs because coughing can dislodge and move the mucus causing the obstruction, altering the sound produced by airflow.
If rhonchi are detected, further tests may be ordered to determine the underlying cause. A chest X-ray is often used to look for signs of pneumonia or changes associated with COPD. A sputum culture may be taken to identify a specific bacterial infection, or pulmonary function tests might be conducted to assess lung capacity and airflow, which is useful in diagnosing conditions like COPD and asthma.
Treatment is directed at the underlying condition causing the rhonchi, so management is tailored to the specific diagnosis. If a bacterial infection is identified, antibiotics will be prescribed. For obstructive conditions such as COPD or asthma, bronchodilators may be used to relax and open the airways, while inhaled steroids can reduce inflammation. Medications known as mucolytics can also be prescribed to thin the mucus, making it easier to clear from the airways through coughing.