What could be causing intermittent cramping under my right rib?

Intermittent Right Upper Quadrant Cramping in a Young Woman

This is most likely painful rib syndrome (also called slipping rib syndrome), a benign musculoskeletal condition that causes intermittent cramping pain under the ribs, particularly with certain movements, and is commonly underdiagnosed in women in their 30s. 1, 2, 3

Most Likely Diagnosis: Painful Rib Syndrome

The clinical presentation of intermittent, movement-related cramping under the right rib in a young woman without trauma strongly suggests painful rib syndrome, which accounts for 3% of general medical referrals and affects 70% women with a mean age of 48 years. 3

Key Diagnostic Features to Confirm:

• Pain that is movement and posture-dependent (worsens with certain positions or activities) 2
• Tenderness on palpation of the costal margin, especially at the end of the lowest floating rib 2, 3
• Reproduction of the exact pain when pressing the tender spot on the rib margin 3
• Pain located in the lower chest or upper abdomen 3

Why This Diagnosis is Safe Without Imaging:

Painful rib syndrome is a safe clinical diagnosis requiring no investigation when the three diagnostic features are present: pain in the lower chest/upper abdomen, a tender spot on the costal margin, and reproduction of pain on pressing that spot. 3 In a study of 76 consecutive patients followed for 4 years, all deaths were from unrelated causes, and all further investigations performed were negative except for incidental gallstones in 3 patients. 3

Red Flags That Would Change Management

You should pursue imaging or specialist referral if any of these are present:

• History of recent trauma or surgery (could indicate actual rib fracture or slipping rib syndrome requiring different management) 4
• Fever, chills, or systemic symptoms (consider infection, including skeletal tuberculosis if travel history to endemic areas) 5
• Constant, progressive pain that doesn't vary with position (consider visceral causes) 2
• Associated respiratory symptoms or dyspnea (consider pulmonary causes) 1
• Pain that awakens from sleep consistently (more concerning for serious pathology) 5

Differential Diagnoses to Consider

Musculoskeletal Causes (Most Likely):

• Costochondritis: inflammation of costochondral junctions, but typically presents with anterior chest wall pain rather than lateral/posterior rib pain 1, 6
• Intercostal muscle strain: can cause similar symptoms but less likely to have reproducible tender point 1
• Slipping rib syndrome: hypermobility of lower ribs causing subluxation, may present with palpable "clicking" or rigid protrusion 1, 4

Visceral Causes (Less Likely Without Other Symptoms):

• Hepatobiliary disease: would typically present with more constant pain, possibly associated with meals 3
• Diaphragmatic hernia: can cause intermittent symptoms but usually associated with GI or respiratory symptoms 7
• Renal/ureteral pathology: would present with more classic colicky pain radiating to groin 8

Management Approach

Initial Conservative Management:

Provide reassurance after clinical diagnosis, explain the benign nature of the condition, and advise on posture modifications to avoid positions that trigger pain. 2 This approach led to symptom resolution in the reported cases. 2

Non-opioid analgesics (NSAIDs or acetaminophen) for pain control during symptomatic episodes. 9

Physical Therapy Considerations:

Osteopathic manipulation techniques and soft tissue mobilization can provide complete resolution in atypical cases that don't self-resolve. 6 A multimodal approach including rib manipulation and instrument-assisted soft tissue mobilization achieved complete pain resolution after three appointments in a case of atypical costochondritis. 6

When to Image:

Imaging is NOT indicated if the classic triad is present and there are no red flags. 3 However, if you must image due to diagnostic uncertainty:

• Ultrasound is preferred for costochondral junction evaluation as it can detect abnormalities not visible on radiographs 1
• Chest radiography has poor sensitivity (missing up to 50% of rib fractures) and is particularly limited for costochondral injuries 1
• CT is reserved for suspected complicated injuries or when serious pathology cannot be excluded clinically 7

Common Pitfalls to Avoid

Do not order extensive investigations before performing systematic firm palpation of the entire costal margin. 3 In one series, 43% of patients with painful rib syndrome had been investigated extensively before referral, and 8 had undergone non-curative cholecystectomy. 3

Do not assume all right upper quadrant pain is gallbladder-related. 3 This leads to unnecessary cholecystectomies in patients with painful rib syndrome.

Do not dismiss the diagnosis if pain persists for years. 3 In follow-up, 70% of patients still had pain after 4 years, but all except 3 had learned to live with it, confirming the benign nature. 3

Warn the patient that symptoms may persist intermittently but are not dangerous. 3 This prevents repeated referrals and unnecessary investigations (33% of patients were re-referred despite firm diagnosis). 3