Differential Diagnosis for Upper Left Quadrant Pain at the End of Breathing

Single Most Likely Diagnosis

• Pleurisy: Pain that occurs at the end of breathing (inspiration) is often related to pleuritic chest pain, which is typically sharp and worsens with deep breathing or coughing. The pleura surrounding the lungs can become inflamed due to various reasons, leading to this type of pain.

Other Likely Diagnoses

• Pneumonia: An infection in the lung can cause pain in the upper left quadrant, especially if the infection is localized to the upper lobe of the left lung. The pain can be worse with deep breathing.
• Pulmonary Embolism (PE): While PE can present with sudden onset of chest pain that worsens with deep breathing, it is less common than other respiratory issues but still a significant consideration due to its severity.
• Costochondritis: Inflammation of the cartilage that connects the ribs to the breastbone can cause chest pain that may worsen with deep breathing or movement.

Do Not Miss Diagnoses

• Myocardial Infarction (MI): Although MI typically presents with chest pain that is more central and may radiate to the arm, jaw, or neck, atypical presentations can occur, especially in women, diabetics, or the elderly. It's crucial not to miss this diagnosis due to its high mortality rate if untreated.
• Aortic Dissection: A tear in the aorta can cause severe, tearing chest pain that can be constant but may worsen with movement or deep breathing. It's a medical emergency that requires immediate attention.
• Pneumothorax: Air in the pleural space can cause the lung to collapse partially or completely, leading to sharp chest pain that worsens with breathing. It can be life-threatening if not recognized and treated promptly.

Rare Diagnoses

• Lung Cancer: While lung cancer can cause chest pain due to tumor growth or metastasis to the chest wall, pleura, or ribs, it is less likely to present as acute pain at the end of breathing unless there is significant tumor burden or associated conditions like pleural effusion.
• Diaphragmatic Hernia: A rare condition where there is a hole in the diaphragm, allowing abdominal organs to move into the chest cavity, which can cause chest pain and breathing difficulties.
• Sickle Cell Crisis: In patients with sickle cell disease, a crisis can cause chest pain due to vaso-occlusion in the lungs, which can mimic other conditions like pneumonia or PE.