Differential Diagnosis for Intermittent Left Sided Pain

Single Most Likely Diagnosis

• Gastroesophageal Reflux Disease (GERD): Although the patient reports no other GI symptoms, GERD can sometimes present with atypical symptoms such as intermittent chest or upper abdominal pain that radiates to the back. The pain's location just below the ribs and its radiation to the back could be consistent with GERD, especially if the patient experiences silent reflux.

Other Likely Diagnoses

• Pancreatitis: Episodes of pancreatitis can cause intermittent pain that radiates to the back. The pain is often constant and severe, but some patients may experience milder, recurrent episodes. The absence of other GI symptoms does not rule out pancreatitis.
• Peptic Ulcer Disease: Similar to GERD, peptic ulcers can cause pain that is intermittent and may radiate to the back. The pain is typically related to eating but can occur at any time.
• Musculoskeletal Pain: The pain could be musculoskeletal in origin, especially if it is non-tender and does not have a clear gastrointestinal pattern. Costochondritis or intercostal muscle strain could cause pain just below the ribs.

Do Not Miss Diagnoses

• Myocardial Infarction or Cardiac Ischemia: Although less likely in a 35-year-old male without risk factors, cardiac causes of chest pain must always be considered due to their potential severity. The radiation of pain to the back can be seen in myocardial infarction.
• Pulmonary Embolism: While the presentation is atypical for pulmonary embolism, it is a condition that could be deadly if missed. However, it usually presents with respiratory symptoms and/or signs of deep vein thrombosis.
• Aortic Dissection: This is a rare but life-threatening condition that can cause severe, tearing chest pain radiating to the back. It is less likely in a young individual without hypertension or aortic disease but should be considered.

Rare Diagnoses

• Splenic Infarction or Abscess: These conditions can cause left upper quadrant pain that radiates to the back. They are less common and usually occur in the context of underlying splenic disease or systemic illness.
• Gastric or Pancreatic Cancer: Although extremely rare in a 35-year-old, these cancers can cause intermittent, non-specific abdominal pain. They would be considered if other diagnoses are ruled out and the pain persists or worsens over time.