For maximum diagnostic yield, history should address the following criteria: Symptom duration Family history of lung disease, especially lung fibrosis History of tobacco use (because some diseases occur mostly among current or former smokers) Current and prior drug use Detailed review of home and work environments, including those of family members A chronologic listing of the patient's employment history, including specific duties and known exposures to organic and inorganic agents (see table Causes of Interstitial Lung Disease), is obtained.