[Bronchoalveolar lavage].

The BAL is one of the essential methods which are performed as a routine diagnostic procedure in interstitial lung disease. Differentiation of cellular components and proteins by this method enables a characterization of alveolitis which is considered to be at the beginning of every disease of the structural elements of the lung. A notable feature is that via an assessment of the intensity of alveolitis it is also possible to arrive at a prognosis. Lavage can also supply important pointers to suitable therapeutic measures. Referring to the literature and own investigations this paper tries to give a review of technique of BAL as well as essential findings and interpretation of this subject.