empyema

empyema Pus in the pleural space between the outer surface of the lung and the chest wall. Empyema is typically a result of a serious bacterial infection. Empyema is a type of pleural effusion, one that is grossly infected. See also effusion, pleural; pneumonia.

empirical

empirical Based on experience and observation rather than on systematic logic. Experienced physicians often use empirical reasoning to make diagnoses, based on having seen many cases over the years. Less-experienced physicians are more likely to use diagnostic guides and manuals. In practice, both approaches (if properly applied) can lead to the same diagnosis.

emphysema

emphysema 1 A lung condition characterized by an abnormal accumulation of air in the lung’s many tiny air sacs (alveoli). As air continues to collect in these sacs, they become enlarged and may break or be damaged and form scar tissue. Emphysema is strongly associated with cigarette smoking, a practice that causes lung irritation. It…