A popping sound from the sternum, or breastbone, is a common experience, often occurring during movements like stretching or adjusting posture. While it can be startling, a popping sternum is frequently a harmless occurrence that does not indicate a serious underlying medical condition. This article explores the typical mechanisms behind this sound and provides guidance on when to seek medical evaluation.
Understanding the Popping Sound
The sternum, a flat bone in the chest, connects to the ribs and collarbones through several joints. These include the sternocostal joints, where the breastbone meets the rib cartilages, and the manubriosternal joint, which joins the manubrium (upper part) to the body of the sternum. The sternocostal joints are synovial joints, characterized by a fluid-filled capsule that facilitates movement. The manubriosternal joint, a cartilaginous joint, also allows slight angulation, contributing to chest wall flexibility.
The audible popping sound in these joints is often due to joint cavitation, a process where dissolved gases within the synovial fluid form and then collapse. Synovial fluid, a viscous substance found in joint cavities, contains various gases. This fluid lubricates the joints and reduces friction during movement.
When the sternum or rib cage undergoes movements like stretching or twisting, the joint surfaces can separate slightly, increasing the volume within the joint capsule. This leads to a rapid decrease in pressure within the synovial fluid. As pressure drops, dissolved gases are released from the fluid, forming microscopic bubbles.
The rapid collapse of these gas bubbles generates the distinct popping or cracking sound. This phenomenon is similar to the sound produced when cracking knuckles and is generally considered a normal occurrence. The sound does not indicate that bones are rubbing together or that joint damage is occurring. After a joint pops, typically around 20 minutes are needed for the gases to re-dissolve into the synovial fluid before it can produce another sound. This process contributes to the mobility and flexibility required for chest wall expansion and contraction, essential for breathing.
When to Seek Medical Advice
While a popping sternum is frequently a harmless event, certain accompanying symptoms suggest the need for medical evaluation. Consult a healthcare professional if the popping is consistently accompanied by persistent pain in the chest or sternal area. Other indicators include localized swelling, redness, or increased tenderness when touching the breastbone.
Seek medical advice if the sternum popping is associated with a noticeable limitation in chest or upper body range of motion. If the popping occurs with significant chest pain that feels like pressure, squeezing, or heaviness, or if it radiates to the arms, back, neck, or jaw, immediate medical attention is necessary. These symptoms can be concerning for conditions beyond musculoskeletal issues.
If the popping is accompanied by shortness of breath, dizziness, cold sweats, unusual fatigue, or nausea, these are signs that should prompt an urgent medical assessment. A fever in conjunction with chest symptoms also warrants a prompt visit to a healthcare provider. These combined symptoms could indicate underlying conditions.
A healthcare provider might investigate causes such as costochondritis, which is inflammation of the cartilage where the ribs meet the sternum, causing sharp chest pain that can worsen with movement or deep breaths. Sternal fractures, typically caused by direct trauma, can also lead to pain, bruising, swelling, and difficulty breathing. Less common possibilities include muscle strains, or certain types of arthritis or inflammatory conditions affecting the joints. An accurate diagnosis from a medical professional ensures appropriate care and peace of mind.