Differential Diagnosis for Pain Below Left Breast
Single Most Likely Diagnosis
- Musculoskeletal strain or costochondritis: This is likely due to the recent history of a bad cough, which can cause strain on the muscles and cartilages of the chest wall, leading to pain. The location below the left breast and the absence of cardiac history make this a plausible explanation.
Other Likely Diagnoses
- Pulmonary embolism (PE) with pulmonary infarction: Although less likely without a history of deep vein thrombosis or recent immobilization, the patient's smoking history increases the risk of PE. The pain could be referred from the lung to the chest wall.
- Gastroesophageal reflux disease (GERD): Smoking can exacerbate GERD symptoms, and the pain can be referred to the area below the breast.
- Pleurisy: Given the recent URI, pleurisy (inflammation of the pleura) could be a cause of the pain, especially if the infection spread to the pleura.
Do Not Miss Diagnoses
- Myocardial infarction (MI): Although the patient has no cardiac history, MI can occur without prior symptoms, especially in smokers. The pain location is atypical but possible.
- Pneumothorax: A spontaneous pneumothorax could occur, especially in smokers, and would require immediate medical attention.
- Esophageal rupture or perforation: This is a rare but life-threatening condition that could cause severe chest pain and requires prompt diagnosis and treatment.
Rare Diagnoses
- Diaphragmatic injury or rupture: This could be a complication of severe coughing but is less common.
- Tumor or metastasis: Although rare, a new onset of pain could be indicative of a tumor, especially in a smoker. However, this would be less likely without other systemic symptoms.
- Sickle cell crisis: If the patient has sickle cell disease, a crisis could cause chest pain, but this would be accompanied by other symptoms like fever, fatigue, and possibly a history of similar episodes.