What are the possible causes of persistent, movement-related chest pain exacerbated by coughing and sneezing, when cardiac and pulmonary evaluations (ECG, echocardiogram, and chest X-ray) are normal and the pain does not respond to antacids or muscle relaxants?
Since the pain worsens with movement, coughing, and sneezing, it is highly likely related to the musculoskeletal system. A common cause is costochondritis, which is inflammation of the cartilage connecting your ribs to your breastbone. Another possibility is a strain of the small muscles between your ribs (intercostal strain). Even though typical muscle relaxants haven't helped, these conditions often require simple rest, warm compresses, or anti-inflammatory medications like ibuprofen. Please discuss these possibilities with your doctor to find a tailored management plan.