Taking a careful clinical history is always the first diagnostic step and is an essential approach to the patient. Specific respiratory symptoms include dyspnoea, abnormal breath sounds (such as wheezing or stridor), hoarseness, cough with or without sputum production, haemoptysis, snoring and chest pain. Each may be of different onset (acute or chronic) or severity, isolated or combined, and sometimes accompanied by general symptoms of disease such as fever, weight loss, oedema, night sweats, nocturia or daytime somnolence.
For some disease areas, additional specific questionnaires can be helpful; for example, in allergic or occupational diseases or suspected sleep apnoea.
Often, the clinical history provides – or at least suggests – the diagnosis prior to investigation.