History
As with any other system a comprehensive history, comprising a characterization of each system, is essential for synthesizing a diagnosis when faced with respiratory problem. A detailed occupational, social and drug history are of special importance in evaluating respiratory symptoms. There are six main presenting symptoms which point to an underlying respiratory disorder (Table 1).
Table 1. Respiratory symptoms
• Cough
• Sputum
• Breathlessness
• Chest pain
• Haemoptysis
• Wheeze
Cough
Cough is a protective reflex and is the result of an effort to expel any accumulated secretions or a foreign substance in the respiratory passages, by means of a release of increased intrathoracic pressure through an open glottis. As such, cough is highly specific to respiratory disorders but it has a low diagnostic sensitivity. However, it should not be dismissed as a «normal winter cough* or a «smoker's usual cough* in anyone. Patient should be asked about its onset, duration, the time of occurrence, any change in frequency and severity, and about the associated expectoration.
As the production of cough depends on an increase in intrathoracic pressure with the glottis closed and then its release through the open glottis, inflammation of the larynx gives the cough a harsh, barking quality. If one of the vocal cords is paralysed the cough loses its explosive character and becomes like a uniform low of cattle (bovine cough).
A bout of coughing may be precipitated by inhalation of cold air, dust or toxic fumes. Recurrent nocturnal cough may suggest either nasopharyngeal dripping or gastroesophageal regurgitation. It is commoner in older people and may be associated with oesoph-ageal stricture, neurological swallowing problems and cardiac failure.