What is the cause of left-sided pain behind and below the ribs that is both aching and sharp?

Left-Sided Pain Behind and Below Ribs: Differential Diagnosis and Management

The most likely diagnosis for left-sided aching and sharp pain behind and below the ribs is a musculoskeletal condition, specifically costochondritis, slipping rib syndrome, or intercostal muscle injury, which collectively account for the majority of nontraumatic chest wall pain presentations. 1, 2

Immediate Priority: Rule Out Life-Threatening Conditions

Before attributing this pain to a benign musculoskeletal cause, you must systematically exclude cardiac and other emergent conditions:

Critical Red Flags Requiring Immediate ECG and Cardiac Workup

• Cardiac ischemia characteristics: Retrosternal pressure or discomfort radiating to left arm, jaw, or neck, accompanied by diaphoresis, nausea, or dyspnea, with pain building gradually over minutes 3
• Sharp pain does NOT exclude cardiac ischemia, particularly in women, elderly patients, and those with diabetes 3, 4
• Obtain an ECG within 10 minutes if any concern for acute coronary syndrome exists 3, 4

Other Life-Threatening Causes to Exclude

• Pulmonary embolism: Acute dyspnea with pleuritic chest pain, tachycardia >100 bpm, or tachypnea 3, 2
• Pneumothorax: Sudden onset dyspnea with sharp pain on inspiration, unilateral absent breath sounds 3
• Acute pericarditis: Sharp pain worsening when lying supine, improving when leaning forward, potentially with friction rub 3, 4
• Splenic pathology: Consider in left-sided lower rib pain, particularly with recent trauma or infectious mononucleosis 1

Most Likely Musculoskeletal Diagnoses

Costochondritis

• Most common cause of nontraumatic musculoskeletal chest wall pain, accounting for 42% of cases 2
• Presents with tenderness of costochondral joints on palpation 3
• Pain typically worsens with movement, deep breathing, or palpation 1

Slipping Rib Syndrome

• Caused by hypermobility of floating ribs (8-12) that are not connected to the sternum 5, 6
• Perform the hooking maneuver: Place fingers under the costal margin and pull anteriorly—positive test reproduces the pain and may produce a clicking sensation 5, 7, 6
• Pain is sharp, located in lower chest and subcostal region, waxing and waning, aggravated by specific movements 5, 8
• Dynamic high-frequency ultrasound can confirm diagnosis by demonstrating slipping of one rib over another during the hooking maneuver 6, 9

Painful Rib Syndrome

• Consists of three features: pain in lower chest or upper abdomen, tender spot on costal margin, and reproduction of pain on pressing the tender spot 7
• Accounts for 3% of new referrals to gastroenterology clinics 7
• This is a safe clinical diagnosis requiring no investigation 7

Intercostal Myofascial Injury

• Involves damage to connective tissues between ribs 1
• Pain reproduced by palpation of intercostal spaces 3

Diagnostic Approach Algorithm

Step 1: History Taking

Obtain specific pain characteristics 2:

• Quality: Sharp pain that increases with inspiration (pleuritic) or position suggests lower likelihood of cardiac ischemia 3
• Duration: Fleeting pain of few seconds is unlikely cardiac 3
• Precipitating factors: Pain worsened by movement, coughing, or specific positions suggests musculoskeletal origin 1, 5
• Associated symptoms: Absence of dyspnea, diaphoresis, nausea, or syncope reduces cardiac probability 3

Step 2: Physical Examination

Systematic palpation is essential 7:

• Palpate all costochondral junctions for focal tenderness 2
• Perform hooking maneuver for ribs 8-12: Place fingers under costal margin and pull anteriorly 5, 7, 6
• Point tenderness renders cardiac ischemia less likely 3
• Pain reproducible by palpation provides highest diagnostic information against angina in patients without previous coronary artery disease 4

Step 3: Imaging Strategy

• Imaging is often unnecessary for patients with reproducible chest wall tenderness and low cardiac risk 2
• Chest radiograph is first-line when imaging is indicated to exclude pulmonary causes 2
• Dynamic high-frequency ultrasound is the diagnostic modality of choice for slipping rib syndrome, demonstrating rib slipping during hooking maneuver 6, 9
• Standard radiographs and CT scans are typically normal in slipping rib syndrome 5, 8

Management Algorithm

For Confirmed Musculoskeletal Pain

Standard management includes 2:

• Acetaminophen or NSAIDs as first-line analgesics 1, 2
• Avoid activities producing chest muscle overuse 2
• Reassurance about benign nature of the condition 2, 7

For Persistent or Refractory Pain

• Physical therapy for muscle strengthening and posture correction 5, 6
• Osteopathic manipulation techniques and instrument-assisted soft tissue mobilization for atypical or persistent costochondritis 2, 6
• Intercostal nerve blocks under ultrasound guidance for slipping rib syndrome 6, 9
• Surgical intervention (rib resection) reserved for refractory cases, though recurrence rates exist 5, 6

Critical Pitfalls to Avoid

• Do not dismiss sharp or positional pain as automatically benign—cardiac ischemia can present atypically, especially in women, elderly, and diabetic patients 3, 4
• Do not rely solely on patient's description of "atypical" pain—this term is problematic and should not be used to exclude cardiac causes 3
• Do not order extensive imaging before performing thorough physical examination—systematic palpation of the costal margin is diagnostic in most musculoskeletal cases 7
• Do not miss slipping rib syndrome—33% of patients with this diagnosis are referred again to hospital for further investigation despite firm initial diagnosis 7
• Avoid unnecessary cholecystectomy—in one series, 8 patients underwent non-curative cholecystectomy before correct diagnosis of painful rib syndrome 7