Differential Diagnosis for Pain in Left Upper Quadrant

Single Most Likely Diagnosis

• Gastroesophageal Reflux Disease (GERD): This condition is characterized by stomach acid frequently flowing back into the tube connecting the mouth and stomach (esophagus). The pain is often felt in the upper abdomen and can radiate to the left upper quadrant, making it a common cause of discomfort in this area.

Other Likely Diagnoses

• Peptic Ulcer Disease: Ulcers in the stomach or duodenum can cause pain that may be localized to the left upper quadrant, especially if the ulcer is located near the stomach.
• Gastritis: Inflammation of the stomach lining can lead to pain in the upper abdomen, including the left upper quadrant.
• Pancreatitis: Although pancreatitis typically causes mid-abdominal pain, it can sometimes radiate to the left upper quadrant, especially if the tail of the pancreas is involved.
• Splenomegaly or Splenic Infarction: Enlargement or infarction of the spleen can cause pain in the left upper quadrant due to the spleen's location.

Do Not Miss Diagnoses

• Myocardial Infarction: Although myocardial infarction (heart attack) typically presents with chest pain, it can sometimes cause referred pain in the left upper quadrant, especially if the inferior wall of the heart is involved.
• Pulmonary Embolism: In rare cases, a pulmonary embolism can cause referred pain in the left upper quadrant if the embolism affects the lower parts of the lung.
• Aortic Dissection: A tear in the aorta's inner layer can cause severe, tearing pain that can radiate to the back and may be felt in the left upper quadrant.
• Diabetic Ketoacidosis: This serious complication of diabetes can cause abdominal pain, including in the left upper quadrant, due to metabolic disturbances.

Rare Diagnoses

• Left Upper Quadrant Hernias: Although rare, hernias in the left upper quadrant can cause pain and discomfort in this area.
• Splenic Artery Aneurysm: Aneurysms of the splenic artery are rare but can cause left upper quadrant pain if they rupture or leak.
• Gastric Cancer: Stomach cancer can cause pain in the upper abdomen, including the left upper quadrant, but it is less common compared to other causes.
• Intestinal Ischemia: Reduced blood flow to the intestines can cause severe abdominal pain, which may be localized to the left upper quadrant in some cases.