Crepitus vs. Crackles — What's the Difference?

Crepitus refers to the crackling or popping sounds and sensations experienced under the skin and joints or in various parts of the body, often resulting from air entering subcutaneous tissues, friction between bones, or the presence of gas in joint spaces. Crackles, on the other hand, are specific to the lungs and are heard with a stethoscope during inhalation, indicating fluid in the airways.

While crepitus can be felt and sometimes heard in cases of joint injuries, osteoarthritis, or after certain surgeries, indicating abnormalities in bone contact or gas in soft tissues, crackles are audible manifestations of conditions like pneumonia, heart failure, or bronchitis, revealing the presence of fluid or secretions in the lungs.

Crepitus is generally detected through physical examination by feeling the joints or tissues, or it can manifest as a sound during movements. Crackles are specifically identified during respiratory examination and can be classified based on their timing in the breath cycle (early, mid, or late inspiratory) and their sound quality (fine or coarse).

The occurrence of crepitus can signal various conditions ranging from benign, such as air trapped under the skin, to serious, like bone fractures or joint damage. Conversely, crackles typically point to respiratory conditions that may require immediate medical attention to address fluid accumulation or infection in the lungs.

Understanding the distinction between crepitus and crackles is crucial for medical professionals in diagnosing and treating underlying conditions. While crepitus might lead to further imaging studies to assess joint or tissue damage, the detection of crackles could prompt tests like chest X-rays to visualize fluid in the lungs.