What Causes Pain Along the Sides of the Chest?

Sharp or persistent pain along the lateral aspects of the chest—often described as occurring “on both sides” or “under the ribs”—can arise from a wide spectrum of conditions, ranging from benign musculoskeletal causes to serious cardiopulmonary or gastrointestinal disorders. Accurate diagnosis hinges on careful clinical evaluation, including symptom characterization (onset, duration, quality, aggravating or relieving factors), physical examination, and targeted diagnostic testing.

Musculoskeletal origins are among the most common etiologies. Costochondritis—an inflammatory condition affecting the costochondral junctions—may produce bilateral, reproducible tenderness over the rib cage, often worsened by movement or palpation. Similarly, intercostal muscle strain, rib fractures (even subtle or non-displaced ones), or myofascial pain syndromes can manifest with lateral chest discomfort that intensifies with deep breathing, coughing, or twisting.

Pulmonary causes must be considered, particularly when pain is pleuritic—sharp, stabbing, and exacerbated by inspiration. Bilateral pleurisy may occur in systemic inflammatory conditions such as lupus or rheumatoid arthritis, or in infectious contexts like viral pleurodynia or tuberculosis. Pulmonary embolism, though more commonly unilateral, can present with bilateral pleuritic pain—especially in high-risk patients—and warrants urgent evaluation given its life-threatening potential.

Gastrointestinal contributors include gastroesophageal reflux disease (GERD), which may refer pain to the lower lateral chest; chronic pancreatitis, where pain radiates to the back and flanks; and hepatobiliary disorders such as cholecystitis or hepatitis, which can cause right-sided flank or subcostal discomfort—though true bilateral involvement suggests systemic or metabolic etiologies like alcoholic liver disease or autoimmune hepatitis.

Less common but critical considerations include bilateral rib metastases (particularly in patients with known malignancy), herpes zoster in its pre-vesicular phase (which may mimic musculoskeletal pain before rash onset), and referred pain from spinal pathology such as thoracic disc herniation or ankylosing spondylitis. Additionally, anxiety-related chest wall tension or hyperventilation syndrome may produce bilateral, non-cardiac chest tightness or aching—often accompanied by other autonomic symptoms.

Because lateral chest pain lacks pathognomonic features, clinicians emphasize red-flag assessment: unexplained weight loss, night sweats, dyspnea, hemoptysis, fevers, or progressive functional limitation warrant prompt investigation—including chest imaging, ECG, laboratory studies (e.g., troponin, liver enzymes, inflammatory markers), and, when indicated, referral to pulmonology, cardiology, or gastroenterology.