Friction Rub Lung Sounds: Understanding the Normal and Abnormal Breath Sounds

When we listen to a patient's breath sounds, it can be helpful to compare them to everyday experiences. For instance, if you take a section of hair and rub it between your fingers next to your ear, you can hear what friction rub lung sounds should sound like. These sounds are caused by the opening and closing of the alveoli in the lungs as the patient breathes.

Crackles, for example, are fine popping noises that occur when fluid fills the alveoli and then opens up with each breath. But what happens when we hear something different or nothing at all? There are four main breath sounds that you should be able to hear in a healthy lung: vesicular, bronchovesicular, tracheal, and rhonchi.

Vesicular sounds are low-pitched blowing or rustling noises that can be heard throughout the majority of the lung fields. Bronchovesicular sounds are lower pitched and hollow sounding, and they can be heard over the smaller bronchioles in the center of the chest and between the shoulder blades on the back. Tracheal sounds are high-pitched and loud, with a hollow quality that is similar to blowing through a big pipe.

Rhonchi, on the other hand, are harsh and hollow sounds that are caused by excess mucus or fluid in the airways. They can be heard over the bronchi, particularly at the top of the sternum below the clavicle.

It's important to note that each area of the lung should have a specific sound, and if any other sound is heard in that location, there may be a disease process occurring. For example, adventitious sounds such as rhonchi or crackles can indicate inflammation or fluid accumulation in the lungs.

In some cases, these abnormal breath sounds may be caused by a condition such as hemothorax, pneumothorax, or pleural effusion, which occurs when there is fluid or air around the lung and it cannot expand properly. Other causes of adventitious sounds include narrowing of the main airways or small air passages, excess mucus or fluid in the airways, or even a mass or inflammation of the lining of the lungs.

As health care providers, it's important to identify and treat the cause of these abnormal breath sounds. We can also educate our patients about what we are hearing and what it usually means, which can help them better understand their condition and take an active role in their treatment.

Friction rub lung sounds