[Diagnostic findings and decision making in the establishing of diagnosis]

Instead of collecting data by far-reaching and unlimited investigations it is recommended to restrict our activity to rationalized and by thought selected examinations. To well appreciate the value of data we must well know the sensitivity and specificity of different examinations. These principles are in practice often not realized and that causes easily diagnostical polypragmasy, even false diagnosis. The author illustrates the mentioned method by examples taken from the process of raising diagnosis in different respiratory diseases (localized infiltrations of the lung, nodular pulmonary disseminations, pulmonary embolism, chronic persistent cough).