Physical examination classically follows a sequence: inspection, palpation (feeling with the hands), percussion and auscultation (listening with a stethoscope). Inspection may show important physical signs such as cyanosis, abnormal breathing patterns, finger clubbing, chest wall deformities, oedema, superior vena cava syndrome or Horner’s syndrome. Palpation may detect, for instance, enlarged lymph nodes, subcutaneous emphysema or points of tenderness. Percussion may reveal areas of dullness (e.g. pleural effusion) or hyperresonance (e.g. pneumothorax) and auscultation may detect abnormal breath sounds, such as wheezes, crackles, or a pleural friction rub, signs that are characteristic of particular respiratory diseases.
The clinical history and physical examination provide the essential clues towards the possible underlying respiratory disease, guiding selection of the appropriate diagnostic investigations: laboratory tests, respiratory function tests, imaging techniques and/or biopsy procedures.