Differential Diagnosis for Absent Breath Sound
- Single most likely diagnosis
- Pneumothorax: This condition, where air leaks into the space between the lung and chest wall, is a common cause of absent breath sounds due to the lung's inability to expand properly.
- Other Likely diagnoses
- Pleural effusion: Fluid accumulation in the pleural space can dampen breath sounds, making them absent or significantly reduced.
- Lung collapse (atelectasis): When a lung or part of it collapses, it cannot expand and fill with air, leading to absent breath sounds over the affected area.
- Pulmonary edema: Fluid in the lungs can make breath sounds appear absent or very distant due to the fluid's interference with sound transmission.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Tension pneumothorax: A life-threatening condition where air continues to leak into the pleural space, causing the lung to collapse completely and potentially shifting the mediastinum, which can lead to cardiac arrest if not promptly treated.
- Massive pulmonary embolism: Although less common, a large clot in the pulmonary arteries can cause significant lung tissue to be under-perfused, potentially leading to areas of absent breath sounds due to the lack of blood flow.
- Rare diagnoses
- Diaphragmatic paralysis: Weakness or paralysis of the diaphragm can lead to reduced or absent breath sounds due to impaired lung expansion.
- Tracheal obstruction: Blockage of the trachea can prevent air from reaching parts of the lung, resulting in absent breath sounds over those areas.
- Congenital conditions (e.g., congenital diaphragmatic hernia in newborns): These conditions can lead to abnormal lung development or positioning, potentially causing absent breath sounds.