[Diagnostic criteria, physiopathology and etiology of intra-alveolar hemorrhage].

In the first part of this article the clinical and paraclinical criteria of intra-alveolar haemorrhages are reviewed. The principal signs and symptoms are dyspnoea, haemoptysis, anaemia and bilateral alveolar and interstitial opacities. Computerized tomography of the chest shows a non-systematized alveolar filling. In the second part, the cytological and histological criteria are considered; they are provided by examination of the alveolar lavage fluid and by lung biopsy. Finally, the main elements in the physiopathology and causes of these haemorrhages are successively described.