Which condition is a must-not-miss differential diagnosis for hemoptysis?

• A. Pulmonary embolism
• B. Common cold
• C. Sinusitis
• D. Bronchitis

Answer: (C)

When assessing hemoptysis, you have to consider whether the bleeding is actually coming from the lower airways or from the upper airway. Blood from the nose or sinuses can drain into the throat and be coughed up as blood-tinged sputum, so sinusitis should be included as a must-not-miss possibility. If sinusitis is suspected, you’d typically see ENT-type symptoms such as facial pressure or pain, purulent nasal discharge, or sinus tenderness, and the chest may appear normal. This distinction matters because the management shifts from pulmonary-directed workup to treating the sinus infection and addressing the upper airway source. The other options are less likely to explain true hemoptysis on their own: a common cold or bronchitis mainly cause cough with mucus but not typically frank blood, and pulmonary embolism, while dangerous and important to consider, is a different clinical pathway that would usually present with more acute chest symptoms and embolic risk features.