Breathlessness. Strategies aimed at identifying and treating the cause of dyspnea

The cause of dyspnea should always be assumed to be physical in nature, although a psychological component may sometimes exist. The workup should include thorough history taking, physical examination, chest radiography, electrocardiography, and determination of arterial blood gas levels or pulse oximetry readings. Although pulse oximetry provides a rough approximation of tissue perfusion, it is less useful for the diagnosis of hypoxia or abnormalities of ventilation. It may be used to assess oxygenation when the cause of dyspnea is known. It is also useful to monitor the clinical course during treatment, which should be directed to the underlying process.