What are the causes of lower rib pain?

Causes of Lower Rib Pain

Lower rib pain is most commonly caused by musculoskeletal conditions, particularly painful rib syndrome (also called slipping rib syndrome) and costochondritis, which together account for the vast majority of cases in patients without trauma history. 1, 2

Primary Musculoskeletal Causes

Painful Rib Syndrome/Slipping Rib Syndrome

• This condition affects ribs 8-10 (the "false ribs") and results from hypermobility of the anterior costal cartilage, causing the rib tips to slip or sublux under the rib above, impinging the intercostal nerves. 3, 4
• The classic triad includes: pain in the lower chest or upper abdomen, a tender spot on the costal margin, and reproduction of pain when pressing the tender spot. 1, 5
• This accounts for approximately 3% of new referrals to general medical/gastroenterology clinics and is significantly underdiagnosed. 5
• Pain is characteristically movement and posture-dependent, worsening with upper-extremity activities, coughing, laughing, or leaning over. 4, 6

Costochondritis

• Inflammation of the costochondral or chondrosternal joints accounts for approximately 42% of all nontraumatic musculoskeletal chest wall pain. 2
• The hallmark diagnostic finding is reproducible tenderness to palpation of the affected costochondral joints. 2
• Can be triggered by chest wall trauma, post-surgical complications (infection or hematoma), or occur spontaneously. 2

Trauma-Related Causes

Rib Fractures

• Lower rib fractures (ribs 7-12) are particularly important because they are associated with abdominal organ injury in 67% of patients with multiple injuries. 7
• In isolated low-energy trauma with normal physical examination, the negative predictive value for abdominal injury is 100%. 7
• Rib fractures correlate directly with pulmonary complications including atelectasis, pneumonia, and respiratory distress, with increased morbidity and mortality especially in patients ≥65 years. 7
• Multiple rib fractures may indicate serious underlying injuries including aortic injury (present in 46% of patients with blunt aortic injury). 7

Gastrointestinal Causes

Esophageal and Gastric Disorders

• Gastroesophageal reflux disease is the most likely gastrointestinal cause of recurring unexplained lower rib/chest pain, accounting for 10-20% of outpatient chest pain presentations. 7
• Pain results from acid stimulation of chemoreceptors or abnormal esophageal contraction/distention. 7
• Can mimic cardiac pain with squeezing or burning quality, lasting minutes to hours, often occurring after meals. 7
• History of NSAID use, potassium supplements, iron, or bisphosphonates should raise suspicion for gastritis or esophageal irritation. 7

Diagnostic Approach Algorithm

Step 1: Clinical Assessment

• Perform systematic firm palpation of the entire costal margin bilaterally to assess for reproducible tenderness and rib mobility. 1, 5
• Assess for trauma history, mechanism of injury, and associated symptoms (dyspnea, dysphagia, weight loss). 7
• In a young patient without exertional component, dyspnea, or radiation to arm/jaw, cardiac causes are extremely unlikely. 1

Step 2: Imaging (When Indicated)

• If physical exam is positive for musculoskeletal pain with reproducible tenderness, no imaging is required. 1
• Dynamic ultrasound has 89% sensitivity and 100% specificity for slipping rib syndrome and should be used when diagnosis is uncertain. 1, 3
• Contrast-enhanced CT is indicated for high-energy trauma, multiple injuries with lower rib fractures, or clinical suspicion of intra-thoracic/intra-abdominal injury. 7
• Plain radiographs detect only 46% of rib fractures compared to CT but may be sufficient for low-risk scenarios. 7

Step 3: Consider Non-Musculoskeletal Causes

• Evaluate for gastrointestinal causes if pain is recurrent without cardiac or pulmonary findings, especially if occurring after meals or with history of NSAID use. 7
• Upper endoscopy should be considered if esophageal cause is suspected, particularly with alarm symptoms (dysphagia, bleeding, weight loss). 7
• Empiric acid suppression therapy is reasonable for suspected GERD without alarm symptoms. 7

Critical Pitfalls to Avoid

• Painful rib syndrome is commonly missed, leading to extensive unnecessary investigations including non-curative cholecystectomies in some cases. 5
• Patients often experience months to years of typical symptoms before correct diagnosis. 6
• In one study, 43% of patients with painful rib syndrome had been investigated extensively before referral, and 33% were re-referred despite firm diagnosis. 5
• Do not assume absence of rib fractures rules out hepatic injury in trauma patients—the absence of fractures cannot exclude organ injury. 7
• Psychological factors (stress, anxiety, depression) may amplify pain perception but do not establish or exclude musculoskeletal diagnoses. 2

Treatment Based on Etiology

For Musculoskeletal Causes

• First-line: Regular acetaminophen as primary analgesic, with NSAIDs (1-2 weeks) as second-line for severe pain. 1, 2
• Avoid movements or postures that worsen pain. 1
• Local ice or heat application as adjunctive therapy. 2
• Low-dose colchicine may be added if symptoms persist despite NSAID therapy. 2
• Provide reassurance that the condition is benign and self-limited—this is the most critical intervention. 1, 8
• For refractory slipping rib syndrome, surgical resection of slipping rib cartilages or rib stabilization may be necessary. 4, 6

For Gastrointestinal Causes

• Trial of empiric acid suppression therapy for suspected GERD without alarm symptoms. 7
• Upper endoscopy if symptoms persist or alarm features present. 7
• Consider esophageal function testing and pH monitoring if endoscopy is normal and symptoms persist. 7